JVC | 250 | User's Manual | JVC 250 User's Manual

JVC 250 User's Manual
SERVICE
MANUAL
Model 250 Projector
2310 Camino Vida Roble
Carlsbad, California 92009
Phone: (760) 929-5300
Fax: (760) 929-5410
DECLARATION OF CONFORMITY
PER ISO/IEC GUIDE 22 AND EN 45014
Manufacturer: Hughes JVC
2310 Camino Vida Roble
Carlsbad, Ca 92009
USA
Hughes-JVC declares that this product conforms to the following Product
Specifications (Directive/Standard):
Safety: EN 60950
IEC 950 (1992)
EMC:
EN 55022 (1988) / CISPR-22 (1986) Class "A"
EN 50082-1 (1992) / IEC 801-2(1991)
EN 50082-1 (1992) / IEC 801-3(1984)
EN 50082-1 (1992) / IEC 801-4(1988)
ANSI C63.4-1992, FCC, Part 15, Class A
In addition, the above product complies with the requirements of the Low Voltage
Directive 73/23 EEC and the EMC Directive 89/336/EEC.
106784 First Edition
May 1999
© Copyright 1999 by Hughes-JVC Technology Corporation.
All worldwide rights reserved.
This manual was produced by Hughes-JVC Technology Corporation and may be revised
without prior notice.
No part of this manual may be reproduced in any form without the express written
permission of Hughes-JVC Technology Corporation.
ILA® is a registered trademark of Hughes-JVC Technology Corporation.
ii
Model 250 Service Manual
Table of Contents
Safety Information .................................................................................... v
Chapter 1 Introduction
1.1 Safety...................................................................................................... 1-1
1.2 Updates................................................................................................... 1-2
1.3 Acronyms ............................................................................................... 1-2
Chapter 2 System Description
2.1
2.2
2.3
2.4
2.5
Introduction ............................................................................................ 2-1
Electrical Section.................................................................................... 2-2
Optical Section ....................................................................................... 2-3
Electronic Section .................................................................................. 2-5
Miscellaneous Items ............................................................................... 2-7
Chapter 3 Electrical
3.1
3.2
3.3
3.4
Safety...................................................................................................... 3-1
Incoming Power Circuit ......................................................................... 3-2
Power Supplies....................................................................................... 3-3
Igniter Assembly .................................................................................... -15
Chapter 4 Optical
4.1
4.2
4.3
4.4
4.5
Arc Lamp................................................................................................ 4-2
Optical Path ............................................................................................ 4-7
ILA® ....................................................................................................... 4-12
Relay Lenses........................................................................................... 4-19
Projection Lens....................................................................................... 4-19
Chapter 5 Electronic
5.1 Safety...................................................................................................... 5-1
5.2 Introduction ............................................................................................ 5-2
5.3 System Controller PCB .......................................................................... 5-3
5.4 Video Processor PCB ............................................................................. 5-11
5.5 Raster Timing Generator PCB ............................................................... 5-16
5.6 Horizontal Vertical Deflection PCB ...................................................... 5-21
5.7 Convergence Deflection PCB ................................................................ 5-28
5.8 Scan Reversal PCB................................................................................. 5-34
5.9 Video Amplifier PCB............................................................................. 5-43
5.10 CRT/Yoke Assemblies.......................................................................... 5-51
5.11 VICs ...................................................................................................... 5-58
5.12 Backplane .............................................................................................. 5-74
Chapter 6 Miscellaneous Items
6.1
6.2
6.3
6.4
Projector Covers..................................................................................... 6-1
Electronics Module Tilt-up .................................................................... 6-2
Ventilation.............................................................................................. 6-3
Air Filters ............................................................................................... 6-4
Model 250 Projector Service Manual
iii
6.5 IR Detectors............................................................................................ 6-4
6.6 EMI Shield ............................................................................................. 6-4
6.7 Cleaning Lenses, ILA® Assemblies, and Mirrors................................... 6-5
Chapter 7 Troubleshooting
7.1
7.2
7.3
7.4
7.5
Safety...................................................................................................... 7-1
LEDs....................................................................................................... 7-2
Diagrams ................................................................................................ 7-12
Error Codes ............................................................................................ 7-22
Troubleshooting Guide........................................................................... 7-25
Chapter 8 Software and Protocol
8.1 Software Updating.................................................................................. 8-1
8.2 Importing/Exporting............................................................................... 8-5
8.3 Terminals and Communication Protocol................................................ 8-10
Chapter 9 Parts
9.1 Replacement Parts List........................................................................... 9-1
9.2 Recommended Spares ............................................................................ 9-3
Glossary ......................................................................................................... A-1
iv
Model 250 Service Manual
Chapter 1---Introduction
1.0 Introductio n
Contents
1.1 Safety............................................................................................................ 1-1
1.2 Updates......................................................................................................... 1-2
1.3 Acronyms Used ............................................................................................ 1-2
The Model 250 Service Manual will provide information on how the each of the
different components function individually and how they work together to take a
source input image and project that image onto the screen. It will provide a list of
the tools and procedures needed to perform necessary adjustments and to remove
and replace components. The tools needed to perform any task are included in the
procedure. The Model 250 Service Manual will provide diagrams and test points
to help in diagnosing and troubleshooting. It will provide illustrations to show
location and proper configuration of major and minor components. This manual
will assist the Hughes-JVC Certified Technician with information to properly
maintain and when necessary, troubleshoot the Model 250 projector. Use the
Model 250 Service Manual in conjunction with the Model 250 User’s Guide.
The User’s Guide covers
!
Installation,
!
Operation,
!
Setup Adjustments
!
Specifications
This Service Manual covers:
!
Projector functional description
!
Service adjustments
!
Removal and replacement of subassemblies
!
Troubleshooting
Together, the Service Manual and User’s Guide provide a qualified service person
with information to properly operate and maintain the projector.
1.1
Safety
This projector contains high voltages in the power supplies and around the CRTs
and high intensity light sources in and around the Arc Lamp and optical path.
Read the entire Safety Chapter at the front of this manual before performing any
adjustments or maintenance.
Model 250 Service Manual
1-1
Chapter 1---Introduction
When performing procedures that call for the projector’s power to be on, always
wear high voltage gloves (ANSI/ASTM 10,000 volt rated) when working around
the CRTs, Arc Lamp or power supplies. Wear safety goggles (rated X5) when
working near the light path from the Arc Lamp or at all times around the
projection lens.
1.2
Updates
Hughes-JVC will periodically provide bulletins and /or manual supplements to
ensure the continued accuracy of this service manual.
1.3
Acronyms Used
ALPS
C
CDB
CH
CPU
CRT
EMI
EPROM
FPGA
F to V
G1
G2
HVDB
Hz
HSYNC
HVDB
HVPS
IIC
ILA®
I/O
I/R
kHz
LED
LVPS
NTSC
PAL
PCB
PLL
PLUGE
RAM
RGB
RGBHV
ROM
RTG
SCB
1-2
Arc Lamp Power Supply
Chrominance
Convergence/Deflection Board
Channel
Central Processing Unit
Cathode Ray Tube
Electromagnetic Interference
Erasable Programmable Read-Only Memory
Field Programmable Gate Array
Frequency to Voltage
CRT Grid 1
CRT Grid 2
Horizontal/Vertical Deflection Board
Hertz
Horizontal Sync
Horizontal/Vertical Deflection Board
High Voltage Power Supply
Inter-Integrated Circuit
Image Light Amplifier
Input/Output
Infrared
Kilohertz
Light Emitting Diode
Low Voltage Power Supply
National Television Standards Committee
Phase Alternating Line
Printed Circuit Board
Phase Lock Loop
Picture Line-Up Generating Equipment
Random Access Memory
Red, Green and Blue
Red, Green, Blue, Horizontal, Vertical
Read Only Memory
Raster Timing Generator
System Controller Board
Model 250 Service Manual
Chapter 1---Introduction
SECAM
SRB
SYNC
TTL
UL
UV
VAB
VCO
VIC
VIN
VPB
VSYNC
VTR
Y
Sequential couleur a memoire (sequencial
color with memory
Scan Reversal Board
Synchronization
Transistor-Transistor Logic
Underwriter Laboratories
Ultraviolet
Video Amplifier Board
Voltage Controlled Oscillator
Video Input Card
Video Input
Video Processor Board
Vertical Sync
Video Tape Recorder
Luminance
Model 250 Service Manual
1-3
Chapter 2---System Description
2.0 System De scription
Contents
2.1 Introduction .................................................................................................. 2-1
2.2 Electrical Section.......................................................................................... 2-2
Incoming Power Circuit ............................................................................. 2-2
Power Supplies........................................................................................... 2-2
Igniter Assembly ........................................................................................ 2-3
2.3 Optical Section ............................................................................................. 2-3
Arc Lamp Module ...................................................................................... 2-3
Optical Path................................................................................................ 2-3
ILA®s.......................................................................................................... 2-4
CRTs .......................................................................................................... 2-4
Relay Lenses .............................................................................................. 2-5
Projection Lens........................................................................................... 2-5
2.4 Electronic Section ........................................................................................ 2-5
VICs ........................................................................................................... 2-5
PCBs........................................................................................................... 2-6
CRT/Yoke Assemblies............................................................................... 2-7
2.5 Miscellaneous Items..................................................................................... 2-7
Projector Covers......................................................................................... 2-7
IR Detectors................................................................................................ 2-7
Cooling Fans .............................................................................................. 2-7
Air Filters ................................................................................................... 2-7
EMI Shield ................................................................................................. 2-8
2.1
Introduction
This chapter is divided into four basic sections: the Electrical Section, the Optical
Section, the Electronic Section and the Miscellaneous Items. Each section gives a
basic description of the components in the section and a description of the
function of those components. This provides an overall view of the projector and
its subsystems for a general understanding of how these systems contribute to the
function of the projector.
Model 250 Service Manual
2-1
Chapter 2---System Description
Figure 2-1 Overview of the Model 250 projector showing major components
2.2
Electrical Section
The electrical section consists of the Incoming Power Circuit, and the Power
Supplies and the Igniter Assembly. The following paragraphs give a list of major
components and a brief description of those components. For a more detailed
description of a component, refer to the chapter and section dedicated to that
particular component.
Incoming Power Circuit
!
Power Cord - The AC power comes in through the Power Cord to the AC
Circuit Breaker.
!
AC Circuit Breaker - The Circuit Breaker connects and disconnects the
projector from electrical energy and protects the projector from overvoltage conditions.
!
AC Line Filter - The AC SF Series Line Filter reduces radiation generated
by a regulated power supply from returning to the AC power source.
Power Supplies
2-2
!
Low Voltage Power Supply (LVPS) - The LVPS supplies standby
voltages and the main system voltages to the projector.
!
Arc Lamp Power Supply (ALPS) - The ALPS supplies power to the
Igniter Assembly while the Arc Lamp is lighting. After the Arc Lamp has
lit, ALPS provides the steady state power to the Arc Lamp. The ALPS
also monitors the condition of the Arc Lamp and sends a feedback signal
to the System Controller PCB if there is a problem.
!
High Voltage Power Supply (HVPS) - The HVPS provides the Anode,
Focus (G3), Black Level (G2), Blanking (G1), and Dynamic Focus voltages
for the CRT.
Model 250 Service Manual
Chapter 2---System Description
Igniter Assembly
The Igniter Assembly provides the high voltage pulse that lights the Arc Lamp
and acts as a link from the Arc Lamp Power Supply to the Arc Lamp after the Arc
Lamp has been lit.
2.3
!
Igniter - The Igniter actually performs three functions. It is a step-up
transformer that supplies the high voltage pulse to light the Arc Lamp. It
also supplies the spark gap for the high voltage pulse. Once the Arc Lamp
is lit, the Igniter acts as a link between the Arc Lamp Power Supply and
the Arc Lamp for steady state operation.
!
Laser Power Supply - The Laser Power Supply provides the voltage for
the spark gap. The spark gap produces a high voltage pulse in the Igniter
that lights the Arc Lamp.
Optical Section
The optical section of the Model 250 consists of the Arc Lamp Module, the
Optical Path, the ILA®, the CRTs, the Relay Lenses and the Projection Lens.
Arc Lamp Module
The Arc Lamp Module supplies high intensity light for the Model 250. Its output
is rated at 2 kW. The Arc Lamp has an expected 50% lifetime (half of initial light
output) of 1000 hours.
Optical Path
The Optical Path consists of all the optical components that transmit, filter,
separate, bend, or straighten the Arc Lamp light. The Optical Path also includes
Polarizing Prisms, Prepolarizing Prisms, Steering Prisms and the 4P Combining
Prism that control the image path inside the Prism Assembly.
!
Cold Mirrors (3) - The Cold Mirrors remove infrared light rays, which
contain most of the heat, from the white light coming from the Arc Lamp.
There are three Cold Mirrors, the first one is located in front of the Arc
Lamp, and the other two are located after the Light Pipe.
CAUTION!
The term "cold mirror" is used because
the mirror passes infrared light and its reflection contains only "cold'
light that does not transmit appreciable heat. As a result of the
absorption of infrared heat radiation, "cold" mirrors get very hot.
!
Light Pipe - The Light Pipe acts as an Integrator to spread out the beam of
light creating a uniform distribution of light across the face of the ILA®.
This will result in a more uniform image on the screen
Model 250 Service Manual
2-3
Chapter 2---System Description
!
Condensing Lenses (2) - The Primary Condensing Lens collects all the
light from the Light Pipe and begins to bend the light rays into a straight
path. The Secondary Condensing Lens works with the Primary
Condensing Lens to collimate or “straighten” the light path before it enters
the Dichroic Beamsplitter Assembly.
!
UV Filter - The UV Filter removes much of the unwanted ultravioltet light
from the white light of the Arc Lamp.
!
Dichroic Beamsplitter Assembly w/ Steering Mirrors - The Dichroic
Mirrors separate white light into Red, Green, and Blue component colors.
The Steering Mirrors direct the separated light beams into the Prism
Assembly.
!
Prism Assembly - The Prism Assembly is a large tank filled with optical
fluid. It houses the following optical components:
"
Pre-polarizing Beamsplitter - The Pre-polarizing Beamsplitter
performs the first part of the polarizing process.
"
Polarizing Beamsplitter - The Polarizing Beamsplitter performs the
final function of the polarizing process.
"
Steering Prisms - When the polarized light leaves the Prism
Assembly and enters the ILA®, the light is modulated by the ILA®.
The modulated light reflects off the ILA® mirror and returns to the
Prism Assembly. Inside the Prism Assembly, the light for the red and
blue reflect off the two Steering Mirrors (one for red, one for blue)
and enter the 4P Combining Optic.
"
4P Combining Optic - The 4P Combining Optic takes the three
colored image lights from the ILA®s and combines them so they
leave the Prism Assembly as a single beam of image light. That
image light continues on to the Projection Lens
ILA®s - Image Light Amplifier (3)
The ILA® is a very important component in the Hughes-JVC projectors. The
ILA® modulates the polarized light from the Arc Lamp. The image light from the
CRT that strikes the input side of the ILA® interacts with the Liquid Crystal layer
of the ILA® to impose an image on the polarized light from the Arc Lamp. The
Model 250 Projector uses the Super Contrast ILA®. The Super Contrast ILA® has
a sequential contrast ratio of 600:1 @ center screen.
CRTs (3)
There are three Cathode Ray Tubes (CRTs), one for each color. The CRT
generates the image light that strikes the input of the ILA®. CRTs are covered in
the Electronics Section.
2-4
Model 250 Service Manual
Chapter 2---System Description
Relay Lens Assemblies (3)
There are three Relay Lenses, one for each color. The Relay Lens focuses the
image light from the CRT onto the photosensitive layer on the input side of the
ILA®. The Relay Lens is physically connected to the CRT (see Figure 2-2).
Front Projection Lens
The Model 250 comes with a choice of four standard lenses. These include a
motorized Zoom Lens or one of three Fixed Lenses. All Projection Lenses have
motorized focus.
2.4
!
Motorized Zoom 2:1-4:1
!
Fixed Lens
"
0.96
"
1.5:1
"
5.6:1
Electronic Section
The electronics section consists of the Input Cards (VICs), the Printed Circuit
Boards (PCBs), and the CRT/Yoke assemblies.
Input Cards (VICs)
There are two standard Input Cards and four optional VICs. The Input Cards are
the first stop for the source input signal. They provide the RGB and Sync
interface for the projector. All VICs are IIC controlled.
Standard VICs:
!
Standard RGBHV VIC - The RGBHV VIC is a straight feed-through with
an IIC selection control.
!
Graphic Enhancer Plus VIC - The Graphics Enhancer Plus VIC is exactly
the same as the RGBHV VIC except for a Menu controlled adjustment for
black on white graphics and text display
Optional VICs:
!
YPbPr VIC - Composite Video Decoding for YPbPr
!
Quad Standard Decoder VIC - Composite Video Decoding (NTSC,
SECAM, and PAL)
!
Quad Standard Decoder and Line Doubler VIC - Composite Video
Decoding (NTSC, SECAM, and PAL) with Line Doubling
!
Four-Input RGBHV - Four- Input RGBHV with IIC controlled Mux
(switcher)
Model 250 Service Manual
2-5
Chapter 2---System Description
Printed Circuit Boards (PCB)
The Model 250 Projector has eight main PCBs:
2-6
!
System Controller PCB - System Controller PCB controls much of the
electronics system. It uses digital and analog circuitry to generate Menu
and internal pattern overlays, and directs convergence correction and
shading information. It controls the IIC data bus that sends geometric
correction and VIC selection data. The System Controller PCB controls
and monitors the status of power supply operations during and after the
projector is powered ON.
!
Raster Timing Generator PCB - The Raster Timing Generator PCB
generates an internal sync for the PLL (Phase Lock Loop) circuitry. It
provides sync detection and selection. It also generates the blanking pulse,
provides horizontal and vertical phase adjustments, and Interlace
detection.
!
Video Processor PCB - The Video Processor PCB receives external image
and sync signals and sends horizontal sync, vertical sync, and green sync
signals to the Raster Timing Generator PCB. It adds Contrast, Brightness,
Sensitivity and Threshold adjustments to the image signals and sends the
image signals, G2 control lines, and G1 bias to the Video Amplifier PCB.
!
Horizontal Vertical Deflection PCB - The Horizontal Vertical Deflection
PCB supplies the deflection waveforms that drive the deflection yokes on
the CRTs for the horizontal and vertical raster. It integrates the geometry
correction such as pincushion, keystone, and vertical linearity onto the
horizontal deflection waveform and adjusts the horizontal and vertical
center raster.
!
Convergence Deflection PCB - The Convergence Deflection PCB
generates the horizontal and vertical convergence correction waveforms. It
generates the horizontal and vertical Dynamic Focus Parabola used by the
High Voltage Power Supply. The Convergence Deflection PCB also
provides the ILA® bias and sensitivity.
!
Scan Reversal PCB - the Scan Reversal PCB reverses the deflection
waveforms for both the horizontal and vertical axes for floor/ceiling
mounting and front/rear mounting. It also provides scan failure detection
to protect the CRT.
!
Video Amplifier PCB - The Video Amplifier PCB amplifies the video
signals and drives the cathodes for all three CRTs. It senses the cathode
beam current and regulates the G1 and G2 for all the CRTs. The Video
Amplifier PCB also provides phosphor protection for all three CRTs and
CRT interface for the Focus, Heater Voltage, and Arc ground.
!
Backplane - The Backplane sits in the back of the Electronics Module.
The System Controller PCB, Raster Timing Generator PCB, Video
Processor PCB and the VICs plug into directly the Backplane PCB. It
Model 250 Service Manual
Chapter 2---System Description
provides an interconnection interface for all the electronic components in
the projector.
CRT/Yoke Assemblies
The CRT/Yoke Assemblies bridge between the Optical and the Electronic
sections. The CRTs could be included in the Optical section because they
produces the image light transmitted to the ILA®s, but they are included in the
Electronic section because they are the end user for the image signals from the
VICs, Video Processor PCB, and Video Amplifier PCB. The CRTs also use the
Anode, Focus, G1, and G2 voltages from the High Voltage Power Supply. The
Yoke Assemblies contains the deflection and convergence coils. The deflection
coils are the end-user for the horizontal and vertical deflection waveforms from
the Horizontal Vertical Deflection PCB. The convergence coils use the
convergence data from the Convergence Deflection PCB.
2.5
Miscellaneous Items
The Miscellaneous Items section consists of components that indirectly support
the main function of the projector.
Projector Covers
All Series 200 projectors including the Model 250 have a front and rear cover.
Both covers can be tilted up and/or removed to service the projector. The covers
should not be opened while the projector is operating without proper safety
protection (review the Safety Chapter).
IR Detectors
The Model 250 can be controlled by a handheld IR Remote Control. The IR
(Infrared) Detectors receive infrared pulses from these remote controls and use
them to control various functions of the projector. One IR Detector is mounted on
the front of the projector, the other is mounted on the System Controller PCB at
the rear of the projector. IR Detectors can receive commands from the remote
control from a range of about 45-ft. line of sight.
Cooling Fans
The Model 250 has eleven cooling fans of various sizes plus a large blower for
the Arc Lamp. The cooling fans maintain thermal stability for the projector. The
Arc Lamp especially depends on the cooling fans. If the fans are not operating
while the Arc Lamp is on, the Lamp will implode from overheating. Many of the
Printed Circuit Boards generate a lot of heat and require airflow from the cooling
fans. The fans provide cooling to the PCBs and CRTs to maintain for stable
operation.
Air Filters
The Model 250 has three air filters (see Figure 2-2). The Air Filters filter the
incoming air to minimize the amount of dust and air-borne particles inside the
Model 250 Service Manual
2-7
Chapter 2---System Description
projector. These air-borne particles can land on optics such as the ILA® and cause
large diffuse dark areas on the screen.
EMI Shield
The Model 250 has an EMI (Electro-Magnetic Interference) Shield that traps and
collects high frequency noise that is radiated by switching power supplies such as
the Arc Lamp Power Supply and the Low Voltage Power Supply. This high
frequency noise can interfere with the operation of radios, televisions, and other
electronic devices.
Figure 2-2 Relative location of CRTs, Relay Lenses, ILA®s, and Air Filters.
2-8
Model 250 Service Manual
Chapter 2---System Description
Model 250 Service Manual
2-9
Chapter 3---Electrical
3.0 Electrical
Contents
3.1 Safety............................................................................................................ 3-1
3.2 Incoming Power Circuit ............................................................................... 3-2
AC Power Cord .......................................................................................... 3-2
AC Circuit Breaker..................................................................................... 3-2
AC EMI Filter ............................................................................................ 3-2
3.3 Power Supplies............................................................................................. 3-3
Low Voltage Power Supply ....................................................................... 3-3
Arc Lamp Power Supply............................................................................ 3-5
High Voltage Power Supply....................................................................... 3-9
3.4 Igniter Assembly .......................................................................................... 3-15
3.1 Safety
CAUTION!
Before performing procedures in this chapter,
review the chapter on Safety at the beginning of this manual.
WARNING!!!
When performing procedures in this chapter
that require projector covers to be off, wear high voltage gloves
(ANSI/ASTM 10,000 volt rated) when working near the CRTs, Arc
Lamp, or power supplies. Wear safety goggles (rated X5) when
working anywhere near the light path from the arc lamp or the
projection lens.
CAUTION!
It is very strongly recommended that setup
data be downloaded (Exported, see section 8.2 Importing/Exporting) before
performing any of the following procedures. Exporting baseline source
setup data to disk is an excellent precautionary measure. It will save the
time of setting up new source file(s) in the case of an unexpected problem.
Model 250 Service Manual
3-1
Chapter 3---Electrical
Left/Right Orientation: When referring to the left or right in this chapter, it is with
reference to standing at the rear of the projector, facing the screen.
Connectors on subassemblies and PCBs have tabs that must be released first
before pulling on the connector. The proper procedure is to push slightly IN on
the connector, then squeeze the tab, then pull the connector out.
3.2. Incoming Power Circuit
AC Power Cord
The Power Cord performs one basic function: to deliver the AC power from the
power source to the projector. It must be configured to meet the Electrical
Specifications for the region the projector will be used. The Power Cord type is
NEMA 5-20, 20A, 250A.
AC Circuit Breaker
The AC Circuit Breaker has two basic functions: one is to connect and disconnect
electrical power from the projector, the second is to protect the projector from
over-voltage conditions.
When the AC Circuit Breaker is in the OFF position, no electrical energy will
reach any part of the projector except for the AC Circuit Breaker. When the AC
Circuit Breaker is in the ON position, electrical energy goes to the AC Line Filter
and on to the Low Voltage Power Supply and Arc Lamp Power Supply. When the
AC Circuit Breaker is in the ON position but the projector has not received the
POWER ON command either from an IR Remote Control or from a PC or Laptop
computer, the projector is in Standby mode. In the Standby mode, the +5.1 V
Standby and the +24 V Standby Voltages maintain power to the CPU chips on the
System Controller PCB, the IR Detectors, and to the cooling fans.
The AC Circuit Breaker is rated at 90-264 Vac (RMS), 50/60 Hz. The current
rating is 13 Amps RMS at 90 Vac.
The power requirements of the Model 250 Projector are 200-264 Vac, 50/60 Hz,
single phase. The power consumption is rated at 2800-Watts maximum.
AC EMI Filter
The AC EMI (Electro-Magnetic Interference) Filter prevents switching noise
from a regulated power supply such as the Low Voltage Power Supply and the
Arc Lamp Power Supply, from returning to the AC power source. This switching
noise interferes with the operation of radios, televisions, and other electronic
appliances
3-2
Model 250 Service Manual
Chapter 3---Electrical
3.3 Power Supplies
All Series 200 projectors including the Model 250 have three power supplies.
These include:
!
Low Voltage Power Supply
!
Arc Lamp Power Supply
!
High Voltage Power Supply
There is a fourth power supply, the Laser Power Supply, but that power supply is
used only for the Igniter Assembly during Arc Lamp lighting.
Low Voltage Power Supply (LVPS)
LVPS - Main Functions:
!
Provides all the low voltages needed by the projector.
!
Provides standby power (+5.1V) when the projector is OFF but the AC
Circuit Breaker is in the ON position.
!
Provides power (+24 V) for all cooling fans.
LVPS - Inputs:
The Low Voltage Power Supply receives AC input power directly from the AC
Line Filter. The input range is from 220 VAC to 240 VAC, at 50/60 Hz.
/LV_ENA - from the System Controller PCB. This signal enables the LVPS when
the System Controller receives a Power On command.
/FAN_ENA - from the System Controller PCB. This signal enables the +24v
standby voltage for the projector fans.
/COVER_ON - signal enables the non-standby outputs.
/ = Active low
LVPS - Outputs:
!
+ 5.1VDC Main
!
+ 5.1VDC Stdby
!
+ 6.2VDC
!
± 15VDC
!
+ 24VDC
!
+ 80VDC
/LV_OK - this diagnostic signal tells the System Controller PCB the status of the
non-standby supply (all the outputs are working or not working).
Model 250 Service Manual
3-3
Chapter 3---Electrical
Figure 3-1 Low Voltage Power Supply I/O Diagram.
LVPS - Operation:
AC power is delivered to the Low Voltage Power Supply from the AC line filter.
The AC is rectified to a DC Voltage, filtered, and goes through a power factor
correction circuit to force the current waveform to follow the voltage waveform.
The +5.1V Standby is on whenever AC power is connected to the projector and
the circuit breaker on the rear panel is in the ON position. When the AC Circuit
Breaker is in the ON position, the LVPS supplies the +5.1 V to the System
Controller PCB. The System Controller PCB drives the /FAN_ENA signal to the
LVPS to turn on the +24V Standby power for the cooling fans. If the System
Controller PCB does not receive a POWER ON command from an IR remote
control or a PC, it waits about 10 minutes and then tells the LVPS (/FAN_ENA
goes high) to shut off +24V Standby power. This shuts off the cooling fans. More
importantly, after the System Controller PCB receives a POWER OFF command
it waits 10 minutes, and then tells the LVPS to shut off the cooling fans. This
gives the Arc Lamp and the PCBs time to cool down to avoid damage or
reduction of operating life.
When the projector receives a POWER ON command from an IR Remote Control
or PC, the System Controller PCB sends the /LV_ENA signal to the LVPS. The
Low Voltage Power Supply needs to receive the /LV_ENA from the System
Controller PCB and the /COVER_ON signal to activate all the non-standby
voltages. These include:
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Chapter 3---Electrical
!
+5.1V for digital components
!
+6.2V for CRT filaments
!
±15V for analog circuits
!
+80V supply used by the High Voltage Power Supply, Video Amplifier
PCB, and the Horizontal/Vertical Deflection PCB.
LVPS - Service Adjustments
There are no service adjustments for the Low Voltage Power Supply.
LVPS - Remove and Replace
Tools Needed:
#2 Posi-drive Phillips-head screwdriver
Parts Needed:
Low Voltage Power Supply - p/n 102520
To remove the Low Voltage Power Supply:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the front cover (see Projector Covers section 6.1).
4. Remove the lower-right-side panel by removing the 5 Pozi-drive screws
securing it.
5. Remove the 5 Pozi-drive screws securing the EMI Shield. Slide the shield
to the left and remove it.
6. Remove J76 (DC Output) and J75 (AC Input) from the left side of the
Low Voltage Power Supply.
NOTE: These connectors may be a little difficult to remove and it may be
necessary to pull the LVPS partly out of the chassis in order to get a better
grip on the connectors.
7. Carefully slide the Low Voltage Power Supply out of the projector.
8. Reinstall the LVPS in reverse order. After installing a new LVPS, it may
be necessary to touch-up the Timing, Geometry, Electronic Focus, ILA®
Bias/Sensitivity, Convergence, G2, and Shading.
Arc Lamp Power Supply (ALPS)
ALPS - Main Functions:
!
Provides ignition power to turn the Arc Lamp ON (via the Igniter).
!
Provides steady state power to maintain the Arc Lamp operation.
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Chapter 3---Electrical
ALPS - Inputs:
AC input power: Directly from the AC Line Filter. The input range is from 220240 VAC, at 50/60 Hz.
/LAMP_ENA - from the System Controller PCB. Turns on the ALPS.
/COVER_ON - signal enabling the Arc Lamp Power Supply.
/LAMP_OK - the input is jumpered at the Arc Lamp Power Supply (tied to
ground) so it is always low.
/ = Active Low
ALPS - Outputs:
3-6
!
+170 VDC output during the boost phase to get Arc Lamp ignition. This
supplies the power for the Igniter.
!
Run Voltage - 25 to 31 V to maintain the arc lamp operation.
!
Current - 70 to 85 amps to maintain the arc lamp operation.
!
LAMP_OUT - Lamp output voltage, positive.
!
LAMP_RTN - Lamp return.
!
/LAMP_LIT - signal to System Controller PCB indicating that the Arc Lamp
is lit.
!
/LAMP_OK - signal to System Controller PCB (no real indication).
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Chapter 3---Electrical
Figure 3-2 Arc Lamp Power Supply signals and voltages.
ALPS - Operation:
Three signals (/LAMP_ENA, /COVER_ON, and /LAMP_OK) are required in
order for the Arc Lamp Power Supply to light the Arc Lamp. The /LAMP_OK
(active low) input is jumpered to ground at the Arc Lamp Power Supply, so it is
always low. The Arc Lamp Power Supply sends the /LAMP_OK to the System
Controller PCB. The System Controller PCB then sends the /LAMP_ENA signal
back to the Arc Lamp Power Supply and activates the Arc Lamp Power Supply.
Once the Arc Lamp Power Supply receives the /LAMP_ENA signal from the
System Controller PCB, it supplies the +170 VDC boost voltage to the primary
coil of the Igniter. The Laser Power Supply charges up a capacitor. When the
capacitor reaches +5.5 kV, a spark gap arcs causing a very high voltage pulse
(approximately 32 kV) to be induced onto the secondary coil inside the Igniter.
This high voltage pulse ignites the Xenon Arc Lamp. Immediately after the Arc
Lamp lights, the voltage from the Arc Lamp Power Supply drops to about 25-31
volts at 70-85 amps. It will stay at this level during normal Arc Lamp operation.
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Chapter 3---Electrical
The Arc Lamp Power Supply sends the
/LAMP_LIT signal back to the System Controller when the Arc Lamp is lit.
The Arc Lamp regulates its output to give a constant Arc Lamp power. If the Arc
Lamp has not lit within 20 seconds (/LAMP_LIT still high), the System
Controller PCB will try once more to re-initiate the sequence. If the Arc Lamp
still fails to light, an error code will appear on the back panel (see section 7.22
Error Codes).
The Arc Lamp Power Supply negative output goes to the Cathode of the Arc
Lamp. The positive output goes to the Anode of the Arc Lamp and is tied to
chassis ground.
The Arc Lamp Power Supply is shielded electrically and magnetically to prevent
noise or disturbances in the CRTs or other circuitry.
Figure 3-3 Arc Lamp Power Supply connections.
ALPS - Service Adjustments
The Arc Lamp Power Supply for the Model 250 is preset at the factory and does
not have any Service Adjustments. The output is programmed for a constant
2 kW. Arc Lamp replacement does not require any electrical readjustments.
ALPS - Remove and Replace
Tools Needed
#2 Pozi-drive Phillips-head screwdriver
Parts Needed
Arc Lamp Power Supply p/n - 105216
To remove the Arc Lamp Power Supply (ALPS):
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off.
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2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the front cover (see section 6.1 Projector Covers ).
4. Remove the lower-right-side panel by removing the five Pozi-drive screws
securing it.
5. Remove the five Pozi-drive screws securing the EMI Shield. Slide the
shield to the left and remove it.
6. Disconnect the INPUT AC plug.
7. Disconnect the two CONTROL SIGNALS cables. The /LAMP_OK signal
jumper is attached to the CONTROL SIGNAL cable by a cable tie. Do not
cut this cable tie.
8. Disconnect the Arc Lamp Power Supply OUTPUT cables from the (+) and
(-) terminals. Take care not to damage the 470µf capacitor across the
output cables. The (+) cable has a red shrink tubing on it; the (-) has a
black shrink tubing on it.
NOTE: The capacitor on the output of the Arc Lamp Power Supply filters
transient spikes from the Arc Lamp when it arcs. Re-attach the capacitor
with the Arc Lamp output leads during reinstallation of new Arc Lamp
Power Supply.
9. Remove the 1 Pozi-drive Phillips-head screws from the bottom of the front
of the Arc Lamp Power Supply. The other screw was removed with the
EMI Shield.
10. Carefully slide the Arc Lamp Power Supply out of the projector.
11. Replace the Arc Lamp Power Supply in the reverse order.
High Voltage Power Supply (HVPS)
HVPS - Main Functions
The High Voltage Power Supply provides the following functions:
!
Phase locked loop circuit for synchronization of the High Voltage Power
Supply to the HVPS_SYNC
!
Generation of Anode voltages (25 kV) for all three CRTs (RGB)
!
Generation of Focus voltage (G3) (7 kV) for all three CRTs (RGB)
!
Generation of G2 (1200 V) supply voltage for the Video Amplifier PCB.
!
Generation of G1 (-150 V) supply voltage for the Video Amplifier PCB.
!
Dynamic Focus Amplifier using horizontal and vertical parabolas supplied to
the High Voltage Power Supply.
!
External CRT Protection and generation of /HV_OK signal
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Chapter 3---Electrical
Figure 3-4 High Voltage Power Supply I/O signals.
HVPS - Inputs
HVPS_SYNC - this signal is generated on the Raster Timing Generator PCB.
Square wave HCT level with 50 or 33% duty cycle. The signal is synchronized to
horizontal sync.
/HV_ENA - The HVPS shutdown signal from the Video Amplifier PCB
(/VA_OK).
H_PARABOLA - The horizontal parabola from the Convergence Deflection PCB
used by the Dynamic Focus Amplifier.
V_PARABOLA - The vertical parabola from the Convergence Deflection PCB
used by the Dynamic Focus Amplifier.
± 15 V. - The power source for the analog circuitry in the High Voltage Power
Supply.
+ 80 V. - The input power for the High Voltage section of the High Voltage
Power Supply.
HVPS - Outputs
G1 Supply - goes to Video Amplifier PCB
G2 Supply - goes to Video Amplifier PCB
/HV_OK - goes to System Controller PCB
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Chapter 3---Electrical
RGB Anode Voltage - goes directly to each CRT
RGB Focus Voltage - goes directly to each CRT
Arc Ground - The Arc Ground protection for each CRT from the Video Amplifier
PCB.
HVPS - Operation
The High Voltage Power Supply has three basic functions.
!
High Voltage Generation
!
Focus Voltages
!
High Voltage and CRT Protection
High Voltage Generation - The High Voltage Amplifier section converts the +80
V from the Low Voltage Power Supply, to 25 kV, and divides it into three outputs
for each CRT. It also uses the HVPS_SYNC signal from the Raster Timing
Generator PCB. This signal is synchronized to the horizontal sync to eliminate
one source of moving noise on the screen. The High Voltage section also supplies
the G2 Voltage for the Video Amplifier PCB.
Focus Voltages - The High Voltage Power Supply receives the horizontal and
vertical parabolas from the Convergence Deflection PCB and adds them together.
They are amplified and sent to the Focus Pack section. The Focus Pack section
couples the amplified parabola waveforms to the Focus Voltages. The Focus Pack
divides the Focus Voltage into three signals and outputs each signal to a CRT.
The DC Focus Voltages are manually adjusted as necessary.
The Arc Ground signal goes to the Video Amplifier PCB and from there, connects
to the CRT. It provides a direct return path for arc currents in the event of internal
CRT arcing.
High Voltage and CRT Protection - The High Voltage Power Supply receives a
/HV_ENA (/VA_OK) signal from the Video Amplifier PCB. This signal goes to
the Protect OR section. The Protect OR section also checks the incoming +80 V.
from the LVPS for an overcurrent condition. The Protect OR section also
monitors the high voltage output for an overvoltage condition. If any of these
checks shows a problem the Protect OR section shuts down the high voltage
amplifier. The Protect OR section outputs the /HV_OK signal telling the System
Controller PCB that the High Voltage Power Supply is functioning properly.
HVPS - Service Adjustments
Normally, the only High Voltage Power Supply adjustments are for CRT Focus.
The CRT Focus Voltage adjusts are mechanical potentiometers located on the
side of the High Voltage Power Supply (see Figure 3-5) that adjust the focus for
each CRT. The CRT Focus Voltage adjustments are detailed in the CRT Section
(see section 5.10 CRT/Yoke Assemblies).
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Chapter 3---Electrical
HVPS - Remove and Replace
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
#2 Pozi-drive Phillips-head screwdriver
small Flathead screwdriver
Parts Needed
High Voltage Power Supply p/n 102566
To remove the High Voltage Power Supply:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the front cover.
4. Remove the High Voltage Power Supply cover (see Figure 3-5) by
removing the 1 Pozi-drive screw that secures the HVPS at the bottom of
the cover and loosening the 2 Pozi-drive screws at the top of the front flap.
Electronic
Focus
Adjustment
Figure 3-5 High Voltage Power Supply cover.
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Chapter 3---Electrical
Table 3-1 HVPS - P45 I/O Pinout
PIN #
1
Description
GND (+80V)
PIN #
9
Description
+15V
2
GND (+15V)
10
-15V
3
GND (-15V)
11
G1 SUPPLY
4
GND (G1)
12
/HV_ENA
5
/HV_OK
13
V PARABOLA
6
H PARABOLA
14
H DRIVE (HVPS_SYNC
7
GND (DAF)
8
+80V
Figure 3-6 High Voltage Power Supply.
5. Carefully slide the cover upward and outward to remove it.
NOTE: Refer to Figure 4-5 for the remainder of this procedure.
6. Disconnect the three CRT Anode Cables.
7. Disconnect P44-G2 Out (at the middle-front of the HVPS).
8. Unsnap the cable clamp at the top of the HVPS.
9. Remove the Anode Cables and the P44 cable from the cable clamp.
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Chapter 3---Electrical
10. Disconnect P45 (“Control”) at upper left of HVPS.
11. Disconnect and label the three Focus cables. The square tabs on these
cables (see Figure 3-6) may have to be lifted up. Gently pry up with a
small Flathead screwdriver.
12. Remove all the cables from the slot in the cable guide located on the left
side of the HVPS.
13. Verify that all plugs and cables are removed and out of the way so the
HVPS is free to be removed.
14. Loosen (do not remove) the two Posi-drive screws (at the bottom of the
HVPS) that secure the HVPS metal housing to the projector.
15. Remove the two Posi-drive screws that hold the top of the HVPS metal
housing to the projector frame.
16. Grasp the HVPS at the bottom and lift upward and outward so that it slides
away from the bottom screws.
17. Reinstall the High Voltage Power Supply in the reverse order.
NOTE: When reinstalling the High Voltage Power Supply:
!
Make sure it slides over the bottom screws and the lip at the top of the
projector frame.
!
Make sure each anode cable “snaps” back into its receptacle. The
receptacles are about 2” inside the hole where the cable goes.
!
Make sure the rear flap on each focus cable connector snaps over the
square socket securely. Wiggle the connector a little to make it fits
securely.
18. Replace the HVPS cover.
19. Replace the projector covers.
20. After replacing the HVPS, check and adjust Electronic Focus as necessary.
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Chapter 3---Electrical
3.4 Igniter Assembly
The Igniter Assembly consists of the Igniter and the Laser Power Supply. The
Igniter and Laser Power Supply are replaced as one unit.
Igniter Assemby - Main Functions:
!
Generates 32 kV pulse to light Arc Lamp Power
!
Acts as link between Arc Lamp Power Supply and Arc Lamp during normal
Arc Lamp operation
Igniter Assembly - Inputs
!
+170 V - From the Arc Lamp Power Supply during Arc Lamp lighting.
!
25-31 V at 70-85 A - From Arc Lamp Power Supply during normal Arc Lamp
operation.
Igniter Assembly - Outputs
!
32 kV - to the Arc Lamp during Arc Lamp lighting.
!
25-31 V at 70-85 A - From Arc Lamp Power Supply during normal Arc Lamp
operation.
Igniter Assembly - Operation
The Igniter has two functions: to light the Arc Lamp and to act as a link between
the Arc Lamp Power Supply and the Arc Lamp during normal Arc Lamp
operation. The Igniter contains the spark gap and the step-up transformer that
supplies the 32 kV pulse that lights the Arc Lamp. During lighting of the Arc
Lamp, the Arc Lamp Power Supply receives the /LAMP_ENA signal from the
System Controller PCB, it sends a +170 VDC boost voltage to the primary coil of
the Igniter. The Laser Power Supply charges up a capacitor. When the capacitor
reaches +5.5 kV, the spark gap arcs causing a very high voltage pulse
(approximately 32 kV) to be induced onto the Igniter Transformer step-up
(secondary) coil. The high voltage pulse goes to the Anode of the Arc Lamp. The
spark generated by the 32 kV pulse creates an arc inside the Xenon bulb that
ignites the Arc Lamp.
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Chapter 3---Electrical
Figure 3-7 Igniter Assembly.
Igniter Assembly - Service Adjustments
There are no service adjustments performed on the Igniter Assembly.
Igniter Assembly - Remove and Replace
Replace the Igniter and the Laser Power Supply as one unit.
Tools Needed
2 - 7/16-inch wrench (one open end wrench)
#1 Pozi-drive Phillips-head screwdriver
Parts Needed
Igniter Assembly p/n 106570
To remove the Igniter Assembly
1. Power the projector Off by IR Remote or PC, and allow the cooling fans
to run until they shut off.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the front cover (see Projector Covers section 6.1).
4. Disconnect the white Anode cable from the output of the Igniter
Transformer using the 7/16-inch wrench. Use one wrench to hold the
inside nut and the other wrench to loosen the outside nut.
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Chapter 3---Electrical
5. Disconnect the orange cable attached to the input side of the Igniter
Transformer using the 7/16-inch wrench. This cable will have black shrink
sleeving on it. It goes to the negative terminal of the Arc Lamp Power
Supply.
6. Disconnect the orange Cathode cable from the Igniter ground post using
the 7/16-inch wrench. Remove the other orange cable that goes to the
positive terminal of the Arc Lamp Power Supply.
7. Remove the five #1 Pozi-drive Phillips-head screws.
8. Lift the Igniter Assembly out of projector.
9. Reverse the procedure to install the Igniter Assembly.
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Chapter 4---Optical
4.0 Optical
Contents
4.1
4.2
4.3
4.4
4.5
Arc Lamp...................................................................................................... 4-2
Optical Path .................................................................................................. 4-7
ILA® ............................................................................................................. 4-13
Relay Lenses ................................................................................................ 4-20
Projection Lens............................................................................................. 4-20
CAUTION! Before performing procedures in this chapter,
review the chapter on Safety at the beginning of this manual.
WARNING!!! When performing procedures in this chapter
that require projector covers to be off, wear high voltage gloves
(ANSI/ASTM 10,000 volt rated) when working near the CRTs, Arc Lamp,
or power supplies. Wear safety goggles (rated X5) when working
anywhere near the light path from the arc lamp or the projection lens.
Dangerous levels of ultraviolet and infrared radiation, dangerous glare, very high
temperatures (180°C to 300°C) and high internal gas pressure are present at the
Xenon Arc Lamp. The lamp is contained in a protective reflector-housing module
and should not be operated outside this housing or outside of the projector.
When replacing the Arc Lamp, replace it as an entire module, as shown in this
manual. Do not open the lamp housing or attempt to replace the Arc Lamp
inside its module! Do not touch the Arc Lamp, or any connections, when the
lamp is ignited or is arcing.
Any servicing of the Arc Lamp must remain restricted to Hughes-JVC Certified
Technicians.
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Chapter 4---Optical
4.1 Arc Lamp
The Arc Lamp is the beginning of the high intensity Light Path. It is located
inside a housing on the right side of the Optical Support Assembly (see Figure
4-5).
Arc Lamp - Main Functions:
The Arc Lamp is a single component composed of a Xenon gas bulb at the center
of a compound elliptical reflector. It supplies the high intensity white light used
by the projector to put a very bright image on the screen. The expected 50% life
(half of initial light output) of an Arc Lamp is approximately 1000 hours.
Arc Lamp - Inputs
!
32 kV pulse to light the Arc Lamp Power Supply
!
2 kW constant power during normal operation
Arc Lamp - Operation
The Arc Lamp Power Supply and the Igniter Assembly work together to produce
a 32 kV pulse that ignites the Arc Lamp. After the Arc Lamp lights, the voltage
from the Arc Lamp Power Supply drops to a constant 25-31 volts at 70-85 amps.
It will stay at this level during normal Arc Lamp operation.
Arc Lamp - Service Adjustments
When a new Arc Lamp is installed, it will need to be aligned using the Arc Lamp
adjustment fixture located inside the Arc Lamp housing (see Figure 4-2).
Arc Lamp Adjustment
Tools Needed
Large Flatblade screwdriver
4-mm Hex-head wrench
Equipment Needed
Minolta Illumination Meter T-1 or equivalent
To align the Arc Lamp:
1. Remove the front cover (see Section 6.1).
2. Loosen the spider lock down bolt (see Figure 4-4).
3. Power the projector ON and let it run for 15 minutes to stabilize.
4. Verify that the "Shutters on Hide" box is checked in the SystemPreferences menu, then use the RGB key and the HIDE key to hide Red
and Blue. This prevents light coming from the Red and Blue ILA®s.
5. Open the fan door of the Arc Lamp Enclosure housing using the large
Flatblade screwdriver to rotate the retaining screws 90° This gains access
to the three Arc Lamp alignment screws. The Arc Lamp fan disconnects
when this door is opened.
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Chapter 4---Optical
CAUTION! Fan disconnection is acceptable for a short
period of time only (preferably <20 minutes--maximum 45 minutes).
WARNING!!! Dangerous levels of ultraviolet and
infrared radiation, dangerous glare, very high temperatures (180°C to
300°C) and high internal gas pressure are present at the Xenon Arc
Lamp. Protect eyes from ultra violet light and infrared light by using X5
(375 to 700 nanometers), ANSI approved, shade goggles when
actually working on the projector near the arc lamp source.
6. Access the "Shutters on Hide" box again from the System-Preferences
menu and uncheck the box, then use the RGB and HIDE keys to hide
Green. This mutes video from the Green CRT but leaves the Green shutter
open to allow Arc Lamp light from the Green ILA® to display on the
screen.
7. Select ILA® Bias from the System-Factory Adjustments menu. Record the
current ILA® bias level. Return to this bias level when this adjustment is
complete. Record only the Green ILA® bias value because Red and Blue
will return to their original levels when Green is reset.
8. Use the up-arrow key and adjust the ILA® bias for Green for maximum
light output.
9. Adjust the Arc Lamp alignment screws (see Figure 4-2) to center the "hot
spot" (brightest area). Figure 4-1 illustrates a "hot spot" on the screen.
NOTE: It is easier to perform the following procedure with one person
standing in front of the screen holding a light meter and another person
making the adjustments to the Arc Lamp.
10. Use the light meter to locate the brightest area or “hot spot”, (see Figure
4-1). Move the light meter around the screen to determine where the hot
spot is located. The “hot spot” will be where the light reading is highest.
11. Adjust screw 1, 2, or 3, (see Figure 4-2) to move the hot spot to the center
of the screen. Moving the “hot spot” will generally require adjusting two
or more screws. Adjusting all three screws adjusts the Arc Lamp on the zaxis. Adjusting the three screws clockwise increases light output and
rolloff.
12. Check for maximum brightness and readjust the z-axis as necessary after
setting the x-axis and again after setting the y-axis.
13. Tighten spider lock down bolt.
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Chapter 4---Optical
Hot spot
off-center
Figure 4-1 Arc Lamp “Hot Spot” (brightest area) is off-center vertically and
horizontally. Adjust to center the “hot spot”.
Figure 4-2 Arc Lamp alignment fixture.
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Chapter 4---Optical
Figure 4-3 Arc Lamp Assembly access door.
Arc Lamp - Remove and Replace
The Arc Lamp Enclosure Assembly consists of the Xenon Arc Lamp module and
blower. Replace the blower together with the Arc Lamp Module.
Tools Needed
7/16 inch wrench
#1 Pozi-drive Phillips-head screwdriver
Diagonal wire cutters (or equivalent)
Parts Needed
Arc Lamp p/n 106298
WARNING!!!
Dangerously bright light and high current
exist in this area of the projector. Before proceeding with the removal of
any subassemblies below, verify that the circuit breaker at the rear of the
projector is turned off and the power plug is removed from the AC outlet.
To Remove the Arc Lamp:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off.
2. Turn the AC Circuit Breaker to the OFF position but leave the AC Power
Cord plugged in to maintain chassis ground.
3. Remove the front cover (see Section 6.1).
4. Disconnect the white Anode cable from the Igniter, using the 7/16-inch
wrench (see Figure 3-7).
Model 250 Service Manual
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Chapter 4---Optical
5. Disconnect the orange Cathode cable from the Igniter, using the 7/16-inch
wrench (see Figure 3-7).
6. Cut the cable tie that is wrapped around the ferrite inductor (metal tube
with white cap below the blower).
7. Disconnect the Arc Lamp door fan cable. This cable runs through the door
and out the bottom of the Arc Lamp Assembly housing (below the right
side inFigure 4-3). It provides power to the Arc Lamp door fan through the
white socket shown to the right of the Arc Lamp fan in Figure 4-3.
Disconnect the cable at the socket connection below the Arc Lamp
housing. Disconnect the top fan cable.
8. Disconnect large blower fan connector.
9. Remove the FA shield from the top of the Arc Lamp. Three #1 Pozi-drive
Phillips-head screws hold the FA shield in place (see Figure 4-4).
10. Remove the two retaining bolts for the Arc Lamp, using a 10-mm socket
and driver.
11. Reverse the procedure to install the Arc Lamp. Check and adjust the Arc
Lamp alignment after replacing. There is no Arc Lamp current adjustment.
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Chapter 4---Optical
Figure 4-4 Arc Lamp Assembly top view.
4.2 Optical Path
Optical Path - Main Function
!
Transports the Arc Lamp high intensity light from the Arc Lamp to the
ILA® and from the ILA® to the Projection Lens
!
Removes the Infrared light that contains most of the heat
!
Removes the unwanted Ultraviolet light
!
Condenses the white light using the Light Pipe for a uniform output
!
Separates the white light into its RGB component colors using Dichroic
Beamsplitters.
!
Polarizes each of the component RGB light beams
!
Combines the component RGB image beams into one beam and delivers
that to the Projection Lens.
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Chapter 4---Optical
Figure 4-5 Upper level view of Optical Path (top view).
Optical Path - Inputs
Arc Lamp high intensity white light
Component RGB Image light from each of the ILA®
Optical Path - Outputs
Component RGB polarized light to the ILA®
Output image light to the Projection Lens
Optical Path - Operation
The light travels from the Arc Lamp into the Optical Path (see Figure 4-5). The
light reflects off a cold mirror and passes through a light pipe. From the Light
Pipe, the light passes through a Condensing Lens .The Condensing Lens also acts
as a XY Positioner. The function of the XY Positioner is to aim the light beam
down the optical path and center it on the face of the ILA®.
After being positioned by the Condensing Lens, the light then reflects off two
more Cold Mirrors, losing more Infrared light. It passes through another
Condensing Lens and into the Dichroic Beamsplitter Assembly.
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Chapter 4---Optical
The Dichroic Beamsplitter Assembly separates the white light into its red, green,
and blue components. Each component light beam goes into the Prism Assembly
where it is polarized.
Light can be viewed as having two electromagnetic components: a Horizontalelectric field and a Vertical-electric field. These fields are perpendicular to each
other. When unpolarized light travels through a polarizing beamsplitter, one of
these fields is reflected and one is transmitted or passes through the beamsplitter.
Upon striking the Prepolarizer, the Vertical field is reflected and is wasted, the Pelectric field is passed through the Prepolarizing Beamsplitter and continues on to
the Main Polarizer. The Main Polarizing Beamsplitter (PBS) is rotated 90° from
the Pre-Polarizing Beamsplitter so the Horizontal field that was transmitted
through the Prepolarizer is reflected by the Main Polarizer. The reflected
polarized light, either red, green or blue, leaves the PBS and goes directly into the
ILA® (see Figure 4-6 and Figure 4-7).
Each color exits the Prism Assembly and enters an ILA® where the Liquid Crystal
in the ILA® rotates the polarized light. The image light striking the input side of
the ILA® modulates the polarized light. The image on the input of the ILA®
originates as a image signal and is transformed into an image by the CRT. The
image from the CRT passes through the Relay Lens and is focused onto the input
side of the ILA®. The modulated image light leaves the output side of the ILA®
and re-enters the Prism Assembly where all three colors combine in the 4P
combining optic. The image light exits the Prism Assembly, passes through the
Projection Lens, and is projected out on the screen (see Figure 4-7).
WARNING!!! Wear safety goggles (rated X5) when
working anywhere near the light path from the arc lamp or the projection
lens.
DO NOT open any of the Optical Support Assembly covers while the
projector is ON. The bright light can cause severe eye damage.
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Figure 4-6 Optical Path
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Figure 4-7 Optical Path
Optical Path - Service Adjustments
Tools Needed
3-mm Hex wrench
Parts Needed
No serviceable parts
The one adjustment that can be performed on the optical path is with the XY
Positioner that moves the #1 Condensing Lens in the X- and Y-axis. The XY
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Chapter 4---Optical
Positioner adjusts the light beam coming out of the Light Pipe so that it projects
squarely onto the face of the ILA®.
NOTE: Do not adjust the XY Positioner unless there is a dark edge visible on
screen.
If the XY Positioner is misaligned, there will be a dark edge on the left, right, top
or bottom edge caused by the edge of the Light Pipe. Perform the Arc Lamp
alignment before adjusting the XY Positioner unless the dark edge makes Arc
Lamp alignment difficult or impossible.
To adjust the XY Positioner:
1. Turn the projector ON and allow it to stabilize for at least 15 minutes.
2. Check the screen for dark edges on the top, bottom, left, or right. Check
the screen with all three colors, using the Variable Flat Field (test pattern
#4) or with ILA® bias only. The dark edge will be obvious in either mode.
3. Remove the front cover.
4. There are four access holes; two with small notches on the top of the hole
and two without notches (see Figure 4-8). Use the two access holes
without notches. These holes are for full aperture ILA®s. The upper access
hole is for vertical adjustment; the lower one is for horizontal adjustment.
5. Insert a 3-mm (long shank) Hex-head wrench into either the horizontal or
vertical access hole and adjust the XY Positioner until the dark edge
moves off the screen.
Figure 4-8 XY Positioner adjust holes.
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4.3 ILA®
ILA® Main functions
!
Modulates image light from the CRT onto the high intensity polarized
light from the Arc Lamp
!
Reflects high intensity light received from the Prism Assembly back into
the Prism Assembly after modulating with image light
!
Adjustable bias voltage and frequency (ILA® Sensitivity)
!
Adjustable offstate with Super Contrast ILA®s
!
Image light from CRT is blocked from output. Image is electrostatically
coupled to output
ILA® Inputs
Arc Lamp light - High intensity polarized Red, Green or Blue light from the
Prism Assembly.
Image light - Red, Green, or Blue image light from the CRTs.
ILA® Bias Voltage and Frequency - 10-13 Vac at 2 kHz
ILA® Outputs
Image light - High intensity polarized image light output to the Prism Assembly
and then to the Projection Lens and screen.
Figure 4-9 ILA® structure
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ILA® Operation
The ILA® plays a critical part in bringing the image to the screen. The ILA®
receives the image light when the CRT projects the image through the Relay Lens
and focuses it onto the photoconductive layer on the input side of the ILA®. The
image does not pass directly through the ILA® but is transferred by a change of
impedance of the photoconductive layer to the Liquid Crystal Layer on the output
side of the ILA®. The light coming from the Arc Lamp enters the output side of
the ILA® and passes through the Liquid Crystal layer. Here the polarized light is
rotated according to the orientation of the liquid crystal molecules. It then reflects
off the mirror and passes back through the liquid crystal layer. The polarized light
it is rotated again and then exits the ILA®. The amount the liquid crystal rotates
the polarized light depends on the ILA® Bias, ILA® Sensitivity (frequency), and
CRT brightness (Sensitivity and Threshold).
ILA® Service Adjustments
ILA® Bias and Sensitivity Adjustment
The ILA® has adjustable bias and frequency (sensitivity). The ILA® bias and
sensitivity are adjusted by software through the menu (see Model 250 User’s
Guide, section 5.6 Setup Adjustments). The ILA® bias is individually adjustable
for each ILA®; the ILA® sensitivity (frequency) adjusts all the ILA®s together.
Super Contrast ILA® Compensator Adjustment
The offstate level can be adjusted on Super Contrast ILA®s. The Compensator
adjustment moves a lever on the top of each Super Contrast ILA® to a null
position. The null position is where the offstate level is as dark as possible. The
Compensator is set at the factory and should not need adjustment. Perform this
procedure when replacing an ILA® assembly or if the Compensator adjustment
lever has been inadvertently moved.
To set the Super Contrast ILA® Compensator:
1. Power the projector ON and allow it to stabilize for at least 30 minutes.
2. Remove the rear cover and tilt the Electronics Module up.
3. Under the System-Preferences menu, verify that the "Shutters on Hide"
box is checked.
4. Use the HIDE key to hide red and blue.
5. Disconnect the connector from the top of the green ILA® assembly.
6. Move the Compensator lever (this lever is just in front of the ILA®
connector) to the right and left until the darkest level appears on the
screen.
7. Reconnect the ILA® connector to the green ILA®.
8. Repeat the above steps for the red ILA® and blue ILA®. Block the light
from the other two ILA®s each time, using the HIDE key.
9. Replace the rear cover.
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NOTE: Reset the ILA® bias after setting the Compensator and check G2
Sensitivity Offset, and Threshold Offset level (see Model 250 User’s
Guide, section 5.8 Black Level G2 and Sensitivity Offset).
ILA® Overlap
This adjustment positions the ILA® assemblies in their sockets so that the image
from each ILA® will overlap (be placed on top of) the other two ILA®s. Make this
adjustment whenever replacing an ILA®.
Tools Needed
4-mm hex-head wrench
Flathead screwdriver
Parts Needed
No parts are needed
To determine if this adjustment is necessary:
1. Power the projector ON and allow it to stabilize for at least 30 minutes.
2. Record the value of the ILA® bias for red, green and blue. Return the
ILA®s to these levels when this procedure is complete.
3. Under the System-Preferences menu, verify that the “Shutters on Hide”
box is unchecked.
4. Use the HIDE key to hide red, green and blue.
5. Increase the ILA® bias for all three colors to maximum. The image on the
screen should be white with some colors at the edges.
6. Check the right, left, top, and bottom edges of the images on the screen.
Using the green image as a reference, compare the edges of the red and
blue image to the green image.
7. NOTE: If the green ILA® has been replaced, reference green to the blue or
red image.)
8. If there is a red or blue border on the left, right, top or bottom edge, the
ILA®s overlap and need adjustment. If both the red and blue overlap, the
border will be yellow. In either case, proceed with the adjustment below.
9. If there is no overlap, reset the ILA® biases to their previous levels from
Step 1.
To perform an ILA® Overlap adjustment:
10. Continue with all three colors hidden.
11. Loosen the two wing nuts at the top of the ILA® assembly (see Figure
4-10).
12. If the overlap is at the left or right, grasp the ILA® assembly and slide it to
the right or left so that the edges coincide with the edges of the other two
ILA® assemblies.
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CAUTION! To avoid damaging the connector,
grasp the ILA® assembly itself, not the connector at the top.
Figure 4-10 ILA® Assembly top view. The overlap screws shown are under
the ILA®. They are visible only after the ILA® assembly is removed.
13. If the overlap is at the top or bottom, be sure the projector is level. Slide
the spring clip (see Figure 4-10) at the top of the ILA® assembly back.
14. Loosen the two hex nuts, using a 4-mm hex-head wrench.
WARNING!!! Always wear an ANSI/ASTM 10,000
volt rated safety glove when working around CRTs due to the High
Voltage present there.
15. Slide the ILA®/Relay Lens/CRT Assembly back and remove the ILA®
assembly (it will slide out with some resistance).
16. There are two adjustment screws at the bottom of the ILA® assembly that
move the ILA® up or down. Turn these screws in or out very slightly to
allow the ILA® to seat lower or higher, as necessary.
17. Reinstall the ILA® assembly, slide the ILA®/Relay Lens/CRT Assembly
forward and replace the spring clip.
18. Repeat Step 4 as necessary.
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19. Retighten the two wing nuts and tighten the two hex nuts.
20. Reset the ILA® biases to their previous levels from Step 2.
ILA® Back Focus Adjustment
The ILA® Back Focus adjustment moves the ILA®/Relay Lens/CRT assemblies
forward or backward as one unit to focus the ILA® output on the screen. When
using a zoom lens this adjustment allows the zoom lens’ tracking to remain
focused on the screen throughout the entire zoom range. Use the Focus Pattern
(Test Pattern #6) to perform this adjustment one color at a time. The procedures
below perform the ILA® Back Focus for the Green lens. The first procedure is for
a zoom lens. The second procedure is for a fixed lens.
For best results, perform ILA® Back Focus procedure with two people: One
person to stand in front of the screen to observe Spacer Balls and the other to
move the ILA®/Relay Lens/CRT assemblies back and forth. This is a factory-set
adjustment, but may need some touch-up in the field.
Tools Needed
4-mm Hex wrench
2.5-mm Hex wrench
Parts Needed
No parts are needed
To adjust the ILA® Back Focus for a Zoom Lens:
1. Power the projector ON and allow to stabilize for at least 15 minutes
2. Remove the Rear Cover and tilt up the Electronic Module.
3. Hide Red and Blue. View Green.
4. Select the Focus Pattern (Test Pattern #6).
5. Select Projection Lens from the menu.
6. Use the up/down arrow keys to zoom the Projection Lens to full telephoto
position (smallest image).
7. Use left and right arrows to focus the projection lens to get sharply
focused spacer balls.
NOTE: Spacer balls separate the layers inside the ILA® Assembly. They
are tiny, random, irregularly shaped spots that are visible throughout the
image. Stand directly in front of the screen and look in the lighter areas of
the image to see the Spacer balls. From throw distances shorter than 4
meters, spacer balls are difficult to see.
8. Zoom the lens to a wide-angle position (largest image).
9. Loosen the wing nut on the Green Relay Lens (or whichever lens is being
focused).
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WARNING!!! Always wear an ANSI/ASTM 10,000
volt rated safety glove when working around CRTs due to the High
Voltage present there.
NOTE: If the ILA®/Relay Lens/CRT assembly cannot be moved close
enough to get a good spacer ball focus, loosen the CRT Lens Stopper Ring
in front of the CRT Holder Ring using a 2.5-mm Hex wrench. Move the
CRT snug against the collar to get additional range, and then, retighten the
collar.
10. Using the 4-mm hex-head wrench, loosen the two hex bolts (see Figure
4-10) on the ILA® assembly in front of the Relay Lens.
11. Slide the Relay Lens/CRT/ILA® assembly forward or backward to achieve
the sharpest spacer ball focus.
NOTE: Do not use the zoom lens focus while performing this step.
12. Repeat Steps 6-11 until the spacer balls stay in focus through the entire
zoom range. The spacer balls may go slightly out of focus in spots while
zooming up or down, but they should be in focus at the smallest and
largest images.
13. Tighten the hex bolts on the Green ILA® Assembly and the wing nut on
the Green Relay Lens.
14. Repeat Steps 9-13 for other colors that need ILA® Back Focusing. Be sure
to hide the other two colors.
To adjust the ILA® Back Focus for a Fixed Lens:
1. Power the projector ON and allow it to stabilize for 15 minutes.
2. Remove the rear cover and tilt up the Electronic Module.
3. View Green. Hide Red and Blue.
4. Select the Focus Pattern (Test Pattern #6).
5. Select Projection Lens from the menu.
6. Use left and right arrows to focus the projection lens to get sharply
focused spacer balls.
7. Put on safety gloves (see Safety section for gloves type) then loosen the
wing nut on the Green Relay Lens, (or whichever lens is being focused).
NOTE: If the ILA®/Relay Lens/CRT assembly cannot be moved close
enough to get a good spacer ball focus, loosen the CRT Lens Stopper Ring
in front of the CRT Holder Ring using the 2.5-mm Hex wrench. Move the
CRT snug against the collar to get additional range, then retighten the
collar.
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8. Loosen the two hex bolts (see Figure 4-10) on the ILA® assembly in front
of the Relay Lens.
9. Slide the Relay ILA®/Lens/CRT assembly forward or backward to achieve
the sharpest spacer ball focus.
NOTE: Do not use the projection lens focus while performing this step.
10. Tighten the hex bolts on the Green ILA® Assembly and the wing nut on
the Green Relay Lens.
11. Repeat Steps 7-10 above for other colors that need ILA® Back Focusing.
Be sure to hide the other two colors.
ILA® Remove and Replace
Each projector has three ILA®s; each located on the front of a Relay Lens.
Tools Needed
4-mm Hex wrench
Parts Needed
Super Contrast
Blue 102630-14
Green 102630-15
Red 102630-16
NOTE: Do not interchange Super Contrast ILA®s. The Compensators on the
ILA®s are color specific and can not be interchanged i.e. the green ILA® can not
be put in the red channel or blue channel.
To Remove the ILA®
1. It is not necessary to power off the projector.
2. Remove the Rear cover. It is not necessary to tilt the Electronics Module
up.
3. Loosen the two Hex nuts using a 4-mm Hex nut wrench and slide the
ILA®/Relay Lens/CRT Assembly back.
4. Loosen the two wing nuts on the ILA® and pull back the spring clip.
5. Disconnect the connector from the ILA® and remove the ILA® assembly
(it will slide out with some resistance).
It will be necessary to reset ILA® bias, and Overlap. ILA® Compensator, G2
setting, and shading for the ILA® being replaced should be checked.
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4.4 Relay Lenses
The Relay Lens focuses the image light received from the CRT on the
photoconductive layer of the ILA® (see Figure 4-9). There are no service
adjustments for the Relay Lens. The Relay Lens rarely needs service and is not
considered a serviceable part.
4.5 Projection Lens
Projection Lens - Input
Combined RGB image light from the Prism Assembly.
Projection Lens - Output
Output image light to the screen
Projection Lens - Operation
The projection lens receives image light from the Prism Assembly. The light is
high intensity light from the ILA® that has been modulated by the image light
from the CRT. After leaving the ILA®s the modulated light travels back through
the Prism Assembly where the red, green, and blue image light are combined. The
Projection Lens focuses this output image light onto the screen. All Projection
Lenses come with motorized focus adjustment.
The Model 250 projector comes with a choice of four standard lens options.
Motorized Zoom Lens
!
!
2:1 - 4:1
Fixed Lenses
0.96: 1
1.5: 1
5.6:1
Optional Lenses
2.4:1 Simulator Lens
Projection Lens - Service Adjustments
There are no service adjustments for the Projection Lens. The focus adjustment,
both rough and fine focus adjustments, are part of the projector setup procedure
(see Model 250 User’s Guide, Setup Adjustments sections 5.4 and 5.5.15)
Projection Lens - Remove and Replace
Tools Needed
5-mm Hex wrench
To remove the Projection Lens:
1. Remove the sponge cover that is around the front of the Projection Lens.
2. Disconnect and label the Projection Lens Focus and Zoom motor cables
(The Focus motor is at the top of the Projection Lens. The Zoom motor is
at the bottom.)
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3. Loosen (do not remove) the Lens holding screw at the right side (see
Figure 4-11) of the Projection Lens.
Figure 4-11 Projection Lens holding screw and removal notch.
NOTE: The 0.96:1 Projection Lens has an adapter sleeve installed on
it. The Projection Lens is installed the same as other Projection Lenses
except the Holding Bolt needs to be loosened more to allow the
Projection Sleeve to clear it.
4. Rotate the Projection Lens left or right as needed so that the notch on the
lens clears the holding screw on the lens holder (see Figure 4-11).
5. Carefully pull the Projection Lens out of the projector.
6. Replace the Projection Lens in reverse order. Be sure to reconnect the
Zoom and Focus motor cables.
NOTE: Use the same procedure to install or remove fixed lenses. Also,
when changing from a zoom to a fixed lens, or vice versa, check the ILA®
Back Focus adjustment (see section 4.3 ILA®).
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Chapter 5---Electronics
5.0 Electronics
Contents
5.1 Safety............................................................................................................ 5-1
5.2 Introduction .................................................................................................. 5-2
5.3 System Controller PCB ................................................................................ 5-3
5.4 Video Processor PCB ................................................................................... 5-11
5.5 Raster Timing Generator PCB ..................................................................... 5-16
5.6 Horizontal Vertical Deflection PCB ............................................................ 5-21
5.7 Convergence Deflection PCB ...................................................................... 5-28
5.8 Scan Reversal PCB....................................................................................... 5-34
5.9 Video Amplifier PCB................................................................................... 5-43
5.10 CRT/Yokes.................................................................................................. 5-51
5.11 VICs ............................................................................................................ 5-58
Standard RGBHV VIC............................................................................... 5-59
Graphics Enhancer Plus VIC...................................................................... 5-61
4-Input (Quad) RGBHV VIC..................................................................... 5-64
YPbPr VIC ................................................................................................. 5-67
Quad Standard Decoder VIC...................................................................... 5-70
Quad Standard Decoder/Line Doubler VIC ............................................... 5-72
5.12 Backplane PCB .......................................................................................... 5-74
5.1
Safety
CAUTION! Before performing procedures in this chapter,
review the chapter on Safety at the beginning of this manual.
WARNING!!! When performing procedures in this chapter
that require projector covers to be removed, wear high voltage gloves
(ANSI/ASTM 10,000 volt rated) when working near the CRTs, Arc Lamp,
or power supplies. Wear safety goggles (rated X5) when working
anywhere near the light path from the arc lamp or the projection lens.
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WARNING!!!
Never look directly at the Arc Lamp, the
lighted Projection Lens or into the lamp housing, from any distance, when
the projector is on. Direct exposure to light of this brightness can cause
severe eye injury.
5.2
Introduction
The Model 250 Electronics System includes nine printed circuit assemblies. They
provide all the controlling voltages and signals to adjust and correct picture
settings, geometry, convergence, and shading (see Chapter 4 of the User’s
Guide). The Electronics System also controls video and sync input signals, LED
displays on PCBs at the rear and side of the projector, two RS-232
communications ports, and two IR receivers for remote control of the projector.
The descriptions in this portion of the manual are based on an overall Electronics
System block diagram and simplified block diagrams for each of the nine printed
circuit assemblies.
Figure 5-1 provides an overall System Block Diagram to show how the Optical
System, Arc Lamp, and Electronics System combine to provide the bright screen
image.
Figure 5-1 Model 250 System Block Diagram.
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Figure 5-2 Model 250 Electronics Module with PCBs (side view).
CAUTION! It is very strongly recommended that setup
data be downloaded (Exported, see section 8.2 Importing/Exporting) before
performing any of the following procedures. Exporting baseline source
setup data to disk is an excellent precautionary measure. It will save the
time of setting up new source file(s) in the case of an unexpected problem.
5.3
System Controller PCB
System Controller PCB - Main Function
!
Enables control for the Low Voltage Power Supply, Arc Lamp and
cooling fans.
!
Fault monitors the HVPS, LVPS, Arc Lamp, and fans.
!
Provides IIC serial bus communication and control between PCBs.
!
Controls Zoom and Focus of the Projection Lens.
!
Generates Menu and Internal Patterns Overlays
!
X and Y Convergence control
!
Threshold and Sensitivity for shading
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Chapter 5---Electronics
!
I/O control for VIC selection
!
Two RS-232 serial interface ports
!
Infrared (IR) remote control interface. Accepts input from front or rear IR
detectors.
!
External 3 color system status LEDs. Green indicates normal, yellow is
standby and red indicates a fault condition.
!
External Service Mode Switch. Pressing this switch during a power-up
sequence brings the system up in a diagnostic mode (for maintenance)
rather than a normal operating mode.
Figure 5-3 Rear of Electronics Module with rear cover and panel removed.
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Figure 5-4 System Controller PCB I/O Diagram for Power Supplies and peripherals.
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Chapter 5---Electronics
Figure 5-5 System Controller PCB I/O Diagram for other PCBs.
System Controller PCB - Inputs
/LV_OK - signal from the Low Voltage Power Supply; it tells the System
Controller PCB that all the non-standby supply voltages are working.
/HV_OK - signal from the High Voltage Power Supply; it tells the System
Controller PCB that all the high voltage supplies are working.
/LAMP_OK - signal from the Arc Lamp Power Supply.
/LAMP_LIT - signal from the Arc Lamp Power Supply; it tells the System
Controller PCB that the Arc Lamp is lit.
ODD_FIELD - Square wave signal from the Raster Timing Generator PCB, with
50% duty cycle that is low during odd fields of an Interlace signal. This signal is
high during noninterlaced signals.
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280_CLK - Square wave signal from the Raster Timing Generator PCB, with
50% duty cycle, synchronized to the horizontal sync at 280 times the frequency of
the horizontal sync. This signal is used by the System Controller PCB to properly
output shading and convergence data.
SOURCE_VALID - Signal from Raster Timing Generator PCB indicates a new
source (or valid source). A high indicates a valid stable signal and a low indicates
a change in input signal.
H_DRIVE - Square wave signal from Raster Timing Generator PCB, with a 50%
duty cycle synchronized to the selected horizontal sync.
V_DRIVE - Square wave from Raster Timing Generator PCB, with a negative
going pulse synchronized to selected vertical sync with a pulse width of about
four horizontal lines.
/FRONT_IR - command signals from the front infrared receiver.
/REAR_IR - command signals from the rear infrared receiver
H_F2V - DC voltage from the Raster Timing Generator PCB, proportional to the
horizontal frequency of the current source.
IIC CLK - IIC clock line, unidirectional clock line for control of synchronous data
transfer of data between PCBs.
IIC DATA - IIC data line, bi-directional serial data line for control of
synchronous data transfer between the System Controller PCB and the Raster
Timing Generator PCB.
+5.1 V Stdby - from the Low Voltage Power Supply when the AC Circuit Breaker
is turned on; it supplies power to the CPU, Interlock Switches, and IR Detectors
before the projector receives the POWER ON command.
+5.1 V - from the Low Voltage Power Supply for all digital circuitry.
±15 V - from the Low Voltage Power Supply for all analog circuitry
GND - Ground
System Controller PCB - Outputs
/LV_ENA - signal to enable the Low Voltage Power Supply non-standby voltages
after the System Controller PCB receives the POWER ON command.
/FAN_ENA - signal to the Low Voltage Power Supply to turn on the +24 V stby
supply to turn on the cooling fans.
/LAMP_ENA - signal to enable the Arc Lamp Power Supply.
RGB_OVER - signal to Video Processor PCB for the On-screen Menu and /or
Internal Test Pattern for red, green, and blue.
OVERLAY - signal to the Video Processor PCB, to switch between internal and
external sources.
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RGB_THRES - red, green, or blue Threshold correction information to the Video
Processor PCB.
RGB_SENS - red, green, or blue Sensitivity correction information to the Video
Processor PCB.
ISYNC - 5 MHz clock to the Raster Timing Generator PCB, used to generate the
internal sync signals
Y_RGB_CONV - control signals to Convergence Deflection PCB for Red, Green,
or Blue Convergence in the y-axis (full-scale correction is about 1 Vpp).
X_RGB_CONV - control signals to Convergence Deflection PCB for Red, Green,
or Blue Convergence in the x-axis (full-scale correction is about 1 Vpp).
CORR_SYNC - Square wave HCT level synchronous signal to the Convergence
Deflection PCB for the horizontal axis.
RGB_SHUT - Signal to operate the red, green, and blue shutters.
LENS_ZOOM - Signal to the zoom motor of the Projection Lens.
LENS_FOCUS - Signal to the focus motor of the Projector Lens.
System Controller PCB - Operation
Startup Functions
When AC Circuit Breaker is powered ON, the Low Voltage Power Supply sends
+5.1 V stdby voltage to the System Controller PCB. The +5.1 V Stdby powers the
CPU and IR Detector so the System Controller PCB can receive and respond to
the POWER ON command. The System Controller PCB sends a /FAN_ENA
signal back to the LVPS turning on the +24 V Stdby to turn the cooling fans on.
When the System Controller PCB receives a POWER ON command from either
the IR remote control or a PC, it sends the /LV_ENA signal to the Low Voltage
Power Supply. This turns on all the non-standby (±15 V, +5.1 V, +6.2 V, +24 V,
+80 V) voltages. After all the non-standby voltages power up, the LVPS sends the
/LV_OK signal back to the System Controller PCB to tell it that all the nonstandby voltages are present.
When the System Controller PCB receives a POWER ON command, it receives
the /LAMP_OK signal from the Arc Lamp Power Supply and sends the
/LAMP_ENA signal back to the Arc Lamp Power Supply to turn it on. The Arc
Lamp lights, and the Arc Lamp Power Supply sends a /LAMP_LIT signal back to
the System Controller PCB (see Figure 5-6).
The System Controller PCB also monitors the status of the High Voltage Power
Supply through the /HV_OK signal.
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Figure 5-6 Power On timing sequence.
Normal Operation Functions
During normal projector operation, the System Controller PCB receives
commands through the remote control, tethered remote control, or a PC.
Commands issued from the IR remote controls are received through IR Detectors
located on the front and rear of the projector. Commands issued from a PC,
Laptop, or Tethered Remote Control are received through the RS-232 serial
interface ports.
The two RS-232 ports, labeled Terminal-in and Control-out, are functionally
almost identical. Both ports can be used to interface with computers, switchers, or
other remote controlling devices using a null modem cable. The difference is,
importing and exporting of configuration data can only be performed through the
Terminal-in. The dipswitch on the back of the System Controller PCB controls
the baud rate (see Figure 7-2).
The System Controller PCB enables the Video Processor PCB to select between
an internal and external source through the OVERLAY signal. The System
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Controller PCB also enables the selected VICs through the IIC bus based on the
VIC selected on the Channel Menu.
The System Controller PCB generates the on-screen menus and test pattern
overlays and sends them to the Video Processor PCB. It sends the X and Y
Convergence correction data to the Convergence Deflection PCB. It sends
Threshold and Sensitivity shading data to the Video Processor PCB for the all
three colors. The System Controller PCB stores all the configuration data such as
Geometry, Convergence, Shading, ILA® Bias and Sensitivity, and G2 settings etc.
in flash memory and allows that data to be exported to, or imported from a floppy
disk.
The System Controller PCB displays system status through a single three-color
LED visible on the back panel. A green light indicates normal operation, the
yellow indicates standby operation, and red indicates a fault or error condition.
The System Controller PCB has an External Service Mode Switch that enables the
operator to switch from the normal operating mode to a diagnostic mode. If there
is a new release of system software, it can be uploaded into the projector by
switching into the diagnostic mode. The procedure for this is in the Software and
Protocol section (see Chapter 8, Software and Protocol).
System Controller PCB - Remove and Replace
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
#0 Pozi-drive Phillips-head screwdriver
Parts Needed
System Controller PCB - p/n 104678
To remove the System Controller PCB:
1. Power OFF the projector by IR Remote or PC, and allow the cooling fans
to run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Disconnect all the external source video cables and control cables.
4. Remove the rear cover.
5. Remove the Back Panel. Remove the nine Pozi-drive Phillips-head
retaining screws using the #1 Pozi-drive Phillips screwdriver.
6. Remove the Connector Bracket by removing the single Pozi-drive
Flathead Phillips-head screw using the #0 Pozi-drive Phillips screwdriver.
7. Pull the black Card Extractor handles back to disconnect the System
Controller PCB connector and pull the PCB out of the Electronics Module.
8. Reverse the procedure to install the System Controller PCB.
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5.4
Video Processor PCB
Video Processor PCB - Main Functions
!
Video signal input and multiplexing
!
Sync signal stripping
!
Overlay signal multiplexing
!
Brightness, Contrast, DC Restore and Blanking
!
Video signal gamma correction
!
Sensitivity and Threshold signal input and control
!
Automatic Contrast, G2, and internal image limiting
Video Processor PCB - Inputs
RGBHV VIC 1,2, & 3 - External image signals from the VICs for red, green, and
blue.
/SEL_VIC - input signal from the RGB VIC used to select the input source from
VIC #1.
RGB_OVER - from the System Controller PCB, the Menu overlays and internal
test patterns for red, green, and blue.
OVERLAY - from the System Controller PCB, switches between internal and
external sources.
CLAMP - Pulse signal from the Raster Timing Generator PCB, tells the Video
Processor PCB the timing and duration of the DC Restore.
BLANKING - Pulse signal from the Raster Timing Generator PCB, it tells the
Video Processor PCB the blanking interval during the scan.
RGB_THRESH - Threshold correction information for red, green, or blue from
the System Controller PCB. Real time data at 0-1 V.
RGB_SENS - Sensitivity correction information for red, green or blue from the
System Controller PCB. Real time data at 0-1 V.
RGB_BEAM - sense signal proportional to the cathode current averaged over
several horizontal lines in the red, green, or blue CRT. The voltage level is +
mV/mA.
/VA_OK - signal from the Video Amplifier PCB telling the Video Processor PCB
the Video Amplifier PCB is receiving red, green, and blue deflections voltages
from the Horizontal Vertical Deflection PCB.
IIC_DATA - IIC data line. Bi-directional serial line for synchronous data transfer
between the System Controller PCB and Video Processor PCB.
IIC_CLK - IIC clock line. Unidirectional clock line for control of synchronous
data transfer over IIC bus.
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Figure 5-7 Video Processor PCB I/O diagram for VICs and Power Supplies.
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Figure 5-8 Video Processor PCB I/O diagram for PCBs.
Video Processor PCB - Outputs
RGB_VID - red, green, or blue video signal to Video Amplifier PCB, typically 01 V.
H&V_SYNC - horizontal sync pulse goes to the Raster Timing Generator PCB.
GRN_SYNC - sync-on-green sync pulse goes to the Raster Timing Generator
PCB.
RESTORE - DC Restore control signal to the Video Amplifier PCB. This signal
controls the DC level of the image signal, clamping it to the proper level on the
Video Amplifier PCB.
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RGB_G2 - red, green, or blue G2 voltage adjust control signal to the Video
Amplifier PCB.
G1_BIAS - G1 adjust control voltage (global adjustment) to the Video Amplifier
PCB.
IIC_INT - IIC interrupt output to System Controller PCB.
Video Processor PCB - Operation
The Video Processor PCB accepts image and synchronizing inputs in either
composite or separate RGBHV component format from the selected VIC. When
the projector receives the power ON command, the System Controller PCB polls
the VICs to determine what VICs are available. It then activates the VIC selected
in the Channel Menu (see section 4-6 in the User’s Guide). The selected VIC
sends a signal (/SEL_VIC) to the Video Processor PCB telling it which VIC is
active.
The Video Processor separates the sync pulses and passes them (H_SYNC and
V_SYNC) on to the Raster Timing Generator PCB. If the source sync type is
Sync-on-Green, the Video Processor strips the horizontal and vertical syncs from
the green input and sends that sync signal (G_SYNC) to the Raster Timing
Generator PCB.
The Video Processor PCB adjusts the image input information with contrast,
brightness, DC restore clamp, and blanking. Contrast changes the peak to peak
amplitude of the External image while keeping the offset (black level) the same.
Brightness shifts the DC level of the External image up or down while keeping
the peak to peak amplitude the same. The DC restore circuit (or clamp pulse)
restores the DC offset (black level) after each horizontal line. Contrast and
Brightness commands come from the IIC data bus. The DC Restore and Blanking
signals come directly from the Raster Timing Generator PCB.
The Video Processor PCB switches in the menu overlays and internal test
patterns. It performs gamma correction adjustments, and applies the shading
(sensitivity and threshold) adjustments. The menu overlay signals create the
displayed menus and test patterns. Menu overlays are generated on the System
Controller PCB. The gamma circuit corrects non-linearities, primarily due to the
ILA®. Gamma correction consists of degrees of black and white boost. The
gamma tracking controls adjust the gain of the image information near the 50%
level.
Sensitivity and Threshold are shading adjustments that correct for non-uniformity
in the CRT and ILA®. Sensitivity adjusts the gain (same as Contrast only local
instead of global) and threshold adjusts the DC offset (black level) (same as
Brightness, only local instead of global) to adjust the dark areas of the red, green,
or blue channel. The sensitivity and threshold commands come from the System
Controller PCB through the IIC bus and adjust both the internal and external
image information. Sensitivity and Threshold are applied to the image
information after the contrast, brightness and gamma correction.
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The G2 voltage accelerates the electrons that are emitted from the cathode of the
CRT. The CRT filament emits the electrons and G1 voltage regulates the amount
of electrons that are emitted from the cathode. The G2 voltage is adjusted through
the menu (Black Level). The Video Processor PCB receives the G2 control data
for each color through the IIC bus and sends an analog voltage to the Video
Amplifier PCB to control the G2 voltage.
The Video Processor PCB protects the CRTs from excess beam currents to
prevent it from burning the phosphor. The Video Amplifier PCB sends a sample
of the beam current (RGB_BEAM) for each CRT back to the Video Processor
PCB. The Video Processor PCB compares this sample to a preset value. If the
sample beam current is higher than the preset value, the Video Processor PCB
reduces the contrast for the CRT with high beam current. If the CRT beam current
is still high, it then reduces the G2 voltage. The maximum beam current is 250 µA
per CRT.
The Video Processor PCB receives the G1_BIAS signal from the System
Controller PCB through the IIC bus and sends a voltage to the Video Amplifier
PCB to set the brightness level.
Figure 5-9 Video Processor PCB LEDs.
Video Processor PCB - Remove and Replace
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
Parts Needed
Video Processor PCB - p/n 105234
To remove the System Controller PCB:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Disconnect all the external source video cables and control cables.
4. Remove the rear cover.
5. Remove the Back Panel by removing the nine Pozi-drive Phillips-head
retaining screws using the #1 Pozi-drive Phillips screwdriver.
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6. Pull the black card extractor handles back to disconnect the Video
Processor PCB connector and pull the PCB out of the Electronics Module.
7. Reverse the procedure to install the Video Processor PCB.
5.5
Raster Timing Generator PCB
Raster Timing Generator PCB - Main Functions
!
Generates an internal sync pulse
!
Detects and selects sync pulses
!
Generates a phase locked sync
!
Generates blanking pulse
!
Provides horizontal and vertical phase adjustments
!
Detects interlaced and generates odd field pulse
!
Selects horizontal frequency band
!
Generates horizontal line count and vertical count
!
Provides IIC interface
!
Generates clamp pulse
!
Detects changes in source
!
Generates HVPS_SYNC signal
!
Enables horizontal deflection (/H_ENA) circuitry
Figure 5-10 Raster Timing Generator I/O diagram for Power Supplies.
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Figure 5-11 Raster Timing Generator for other PCBs.
Raster Timing Generator PCB - Inputs
V_SYNC - input vertical sync from the Video Processor PCB.
H_SYNC - input horizontal sync from the Video Processor PCB.
G_SYNC - Sync-on-Green sync stripped from green video signal at the Video
Processor PCB.
ISYNC - 5 MHz clock from the System Controller PCB used to generate the
internal sync.
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IIC_CLK - IIC clock line. Unidirectional clock line for control of synchronous
data transfer over the IIC bus.
IIC_DATA - IIC data line. Bi-directional serial line for synchronous data transfer
between System Controller PCB and Raster Timing Generator PCB.
+15 V (two inputs) - input power from LVPS for analog circuitry including the
Phase Lock Loop (PLL) circuit.
-15 V (two inputs) - input power from LVPS for analog circuitry including the
Phase Lock Loop (PLL) circuit.
+5.1 V - input power from the LVPS for digital circuitry
Raster Timing Generator PCB - Outputs
SOURCE_VALID - signal to the System Controller PCB, indicates a new or valid
source. High = valid, stable source, low = change in input source.
ODD_FIELD - square wave to System Controller PCB, with 50% duty cycle that
is high during the odd field of an interlaced signal and low for non-interlaced
signals.
280_CLK - square wave to System Controller PCB, with 50% duty cycle,
synchronized to the horizontal sync at 280 times the frequency of the horizontal
sync. This signal is used by the System Controller PCB to properly output shading
and convergence data.
CLAMP - a negative-going image clamp signal to the Video Processor PCB, with
about 3% duty cycle.
BLANKING - right, left, top, and bottom blanking signal to the Video Processor
PCB.
H_BAND(0-3) - horizontal frequency band lines to the Horizontal Vertical
Deflection PCB.
Band 0 = 15 - 24 kHz
Band 1 = 24 - 28 kHz
Band 2 = 28 - 55 kHz
Band 3 = 56 - 90 kHz
/H_ENA - enables the horizontal deflection amplifier on the Horizontal Vertical
Deflection PCB, Low = enabled deflection; high = disabled deflection.
H_FV2 - a DC voltage to the Horizontal Vertical Deflection PCB and System
Controller PCB, proportional to horizontal frequency.
H_DRIVE - square wave to the Horizontal Vertical Deflection PCB, 50% duty
cycle synchronized to the selected horizontal sync. This signal provides a sample
of the horizontal sync to the horizontal amplifier on the Horizontal Vertical
Deflection PCB.
HVPS_SYNC - synchronization pulse for High Voltage Power Supply,
synchronized with the selected horizontal sync at the same, half, or one third the
frequency.
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V_DRIVE - square wave negative going pulse to the Convergence Deflection
PCB, synchronized to the selected vertical sync with the pulse width of about four
horizontal periods.
Raster Timing Generator PCB - Operation
The Raster Timing Generator PCB generates a square wave that is phase-locked
to the horizontal sync pulse. It generates timing signals such as Blanking that goes
to the Video Processor PCB and Video Amplifier PCB, and the H_DRIVE signal
that goes to the Horizontal Vertical Deflection PCB. The PLL (Phase Locked
Loop) locks these signals to the horizontal sync signal. The Raster Timing
Generator PCB has LEDs that indicate the type of sync pulse received and the
status of the PLL circuit (see Figure 5-12).
The H_DRIVE signal supplies a sample of the horizontal scan frequency to the
horizontal deflection amplifier on the Horizontal Vertical Deflection PCB for
timing of the horizontal deflection waveform.
The Raster Timing Generator PCB checks the incoming syncs to make sure they
are valid signals and within the frequency ranges (15 - 90 kHz - horizontal, and 45
- 120 Hz vertical). If the syncs are out of range, or there is no sync pulse, the
Raster Timing Generator PCB generates an internal interlaced sync at 33.7 kHz
horizontal and 60 Hz vertical.
The Raster Timing Generator PCB tells the System Controller PCB when there
has been a source change using the SOURCE_VALID signal.
The Raster Timing Generator PCB generates the Blanking signal, and the
horizontal Phase signal.
!
Blanking shuts off the image during times where there is no active video. The
Blanking signal pulls the G1 voltage on the Video Amplifier PCB down far
enough to make the CRT shut off. The Raster Timing Generator PCB receives
the top, bottom, left, or right blanking command on the IIC bus and sends the
appropriate Blanking signal to the Video Processor PCB. The Raster Timing
Generator PCB receives the Blanking adjustment commands on the IIC bus.
!
The horizontal Phase signal adjusts the on-screen image horizontally to
compensate for different phase requirements at different horizontal scan
frequencies. The Raster Timing Generator PCB receives this command from
the System Controller PCB on the IIC bus.
The Raster Timing Generator PCB sends several signals such as 280_CLOCK
signal to the System Controller PCB to correctly set the timing for shading and
convergence data.
In order to combat noise caused by crosstalk between supplies (beat patterns) the
High Voltage Power Supply is phase locked to the incoming horizontal frequency
by the HVPS_SYNC signal.
The horizontal flyback time gets shorter as the horizontal scan frequency
increases. The Raster Timing Generator PCB works together with the Horizontal
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Vertical Deflection PCB to break the range of horizontal scan frequencies into
four smaller ranges called bands (see Figure 5-12).
Figure 5-12 LEDs on the Raster Timing Generator PCB.
Raster Timing Generator PCB - Remove and Replace
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
Parts Needed
Raster Timing Generator PCB - p/n 105238
To remove the Raster Timing Generator PCB:
1. Power OFF the projector by IR Remote or PC, and allow the cooling fans
to run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Disconnect all the external source video cables and control cables.
4. Remove the rear cover.
5. Remove the Back Panel. Remove the nine Pozi-drive Phillips-head
retaining screws using the #1 Pozi-drive Phillips screwdriver.
6. Pull the black Card Extractor handles back to disconnect the Raster
Timing Generator PCB connector and pull the PCB out of the Electronics
Module.
7. Reverse the procedure to install the Raster Timing Generator PCB.
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5.6
Horizontal Vertical Deflection PCB
Horizontal Vertical Deflection PCB - Main Functions
!
Drive the main horizontal deflection coils to provide horizontal raster scan
for the CRTs
!
Drive main vertical coils to provide vertical raster scan for the CRTs
!
Horizontal raster centering for all three colors
!
Switch mode power supply generating the required proportional DC
supply
!
Horizontal width adjustment
!
Horizontal retrace switch network
!
Left/right pincushion and keystone correction
!
Vertical linearity adjustments individually for all three colors.
!
Vertical raster centering for all three colors
!
IIC interface.
Horizontal Vertical Deflection PCB - Inputs
H_BAND:0-3 - horizontal scan frequency bands, from Raster Timing Generator
PCB.
/H_ENABLE - from the Raster Timing Generator PCB, enables the horizontal
deflection supply. Low = enabled deflection, High = disabled deflection.
H_DRIVE - square wave from the Raster Timing Generator PCB, 50% duty cycle
synchronized to the selected horizontal sync.
H_F2V - a DC voltage from the Raster Timing Generator PCB, proportional to
horizontal frequency
H_LOCK (neg.) - Deflection Yoke Connector Interlock return from the Scan
Reversal PCB.
DEFL_OK - deflection status signal from the Scan Reversal PCB (high = good,
(about 2 V), low = no scan).
V_RAMP - vertical ramp waveform from the Convergence Deflection PCB,
(about 4 Vpp).
V_PARAB - vertical parabola waveform from the Convergence Deflection PCB,
(about 4 Vpp).
FRONT/REAR - front or rear projection status line from the Scan Reversal PCB.
(FRONT = low, REAR = high).
FLOOR/CEILING - floor or ceiling projection status line from the Scan Reversal
PCB. (FLOOR = low, CEILING = high).
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IIC_CLK - IIC clock line
IIC_DATA - IIC data line
IIC_SINT - IIC interrupt
±15 V - input power from the Low Voltage Power Supply, for the analog
circuitry.
+5.1 V - input power from the Low Voltage Power Supply, for the digital
circuitry.
Figure 5-13 Horizontal/Vertical I/O Diagram.
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Figure 5-14 Horizontal/Vertical I/O Diagram for Scan Reversal and Video
Amplifier PCBs.
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Vertical Adjustment Pots
Figure 5-15 Physical layout of the Horizontal/Vertical PCB (note the Vertical Size
Adjustment Pots (Red-137, Grn-148, and Blu-160) on the lower right).
Horizontal Vertical Deflection PCB - Outputs
/SWEEP_OK - signal to the Video Amplifier PCB, derived from the H_ENA
signal from the Raster Timing Generator PCB, and the DEFL_OK from the Scan
Reversal PCB.
WIDTH_CTRL - a DC voltage to the Convergence Deflection PCB that adjusts
the parabola waveforms used for geometric correction (about 4 V max.).
H_RGB(pos.) - horizontal deflection waveform return from the Scan Reversal
PCB. A DC offset that shifts the reference for red, green, and blue image for
centering.
H_OUT_FLYB - output waveform to the Scan Reversal PCB for the horizontal
deflection coils on the CRTs.
H_LOCK (pos.) - +15 V to the Scan Reversal PCB for deflection yoke connector
interlock.
V_RGB (pos.) - positive vertical deflection voltage to the Scan Reversal PCB.
V_RGB (neg.) - negative vertical deflection voltage to Scan Reversal PCB.
±15 V - pass through voltage from Low Voltage Power Supply to Scan Reversal
PCB to power analog circuitry.
+5.1 V - pass through voltage from Low Voltage Power Supply to Scan Reversal
PCB to power digital circuitry.
H_CUR_FDBK - current feedback to horizontal waveform amplifier.
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Horizontal Vertical Deflection PCB - Operation
The Horizontal Vertical Deflection PCB consists of a RGB horizontal deflection
amplifier and separate vertical deflection amplifiers.
The Horizontal Deflection Amplifier
The horizontal deflection amplifier is a switching mode power supply that varies
according to the input horizontal sync frequency. The horizontal supply generates
the sawtooth current-driven waveform that drives the horizontal deflection coils
on the CRT. The sawtooth current waveform creates the raster on the CRT. The
horizontal amplifier also generates the retrace waveform portion of the raster.
The horizontal deflection sawtooth waveform is modulated by other waveforms
that perform geometric correction such as Pincushion, Keystone, Horizontal
Centering, Horizontal Linearity and Horizontal Width adjustment. The Width
Control voltage also goes to the Convergence Deflection PCB to adjust the
geometric correction parabolas.
The H_F2V signal converts the input horizontal scan frequency to a voltage that
switches from one band (see explanation of bands in the Raster Timing Generator
PCB Operation section) to the next depending on the horizontal scan frequency.
This adjusts the retrace time to correspond to the input horizontal frequency. The
output of the horizontal supply is H_OUT_SUPPLY that goes on to the Scan
Reversal PCB.
CRT Protection
The Horizontal Vertical Deflection PCB uses the H_LOCK+, H_LOCK- and
DEFL_OK signal to protect the CRTs from being damaged if the deflection
waveforms are lost. Refer to the CRT Protection section in Chapter 9 for a
complete discussion of these and all the signals associated with CRT Protection.
The Horizontal Vertical Deflection PCB receives the DEFL_OK signal from the
Scan Reversal PCB indicating the presence of the horizontal and vertical
deflection waveforms. If there is a failure of any of the Deflection Yokes
(horizontal or vertical), a current sense line on the Scan Reversal PCB forces
DEFL_OK low. On the Horizontal Vertical Deflection PCB, the DEFL_OK
signal becomes /SWEEP_OK and is sent to the Video Amplifier PCB where it
shuts down G1. If DEFL_Ok is forced low, or if /H_ENA is forced high,
/SWEEP_OK goes high. The /SWEEP_OK goes to the Video Amplifier PCB. If it
goes high, it shuts down the G1 voltages and G2 Regulator circuit (see
Troubleshooting, CRT Protection section).
Vertical Deflection Amplifier
The vertical deflection sawtooth waveform is generated on the Convergence
Deflection PCB and timed to the vertical sync by the V_DRIVE signal from the
Raster Timing Generator PCB. The Convergence Deflection PCB sends this
waveform along with a parabola waveform V_PARAB to the vertical deflection
amplifier on the Horizontal Vertical Deflection PCB. The Horizontal Vertical
Deflection PCB takes V_RAMP, amplifies it and adds geometric correction with
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the V_PARAB waveform. The output waveform V_RGB+ goes to the Scan
Reversal PCB and then drives the Vertical Deflection Yokes. The Vertical
Deflection Yoke return signal to the Horizontal Vertical Deflection PCB is
V_RGB-.
Horizontal Vertical Deflection PCB - Service Adjustments
Vertical Size Adjustment
Tools Needed
Miniature Potentiometer-Trimmer Adjustment tool
To adjust the Vertical height (see Figure 5-15):
1. Remove the rear cover and pull the Interlock switch out to the Service
Mode position.
2. Power ON the projector by IR Remote or PC, and allow it to stabilize for a
minimum of 15 minutes
3. Use the X-hatch test pattern.
NOTE: The green image is the reference to which the red image and blue
image will be matched. The green height pot should not need adjustment
except when the green CRT has been replaced.
4. Hide Blue and view Red and Green.
5. If Red is higher than Green at the top and lower than Green at the bottom
of the X-hatch image, or If lower than Green at the top and higher at the
bottom, adjust Red vertical pot (R137) to correct the error.
Vertical Adjustment Potentiometers (see Figure 5-15)
Red - R137
Green - R148
Blue - R160
Figure 5-16 Red image needs vertical adjustment (decrease).
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Figure 5-17 Red image needs vertical adjustment (increase).
If Red is higher than Green at the top and bottom, or lower than Green at
the top and bottom, the Red image may not being centered correctly. This
can be corrected with the centering adjustment (see Model 250 User’s
Guide, Chapter 5).
Figure 5-18 Red image needs vertical centering.
If the Red height pot does not completely eliminate the difference in
height between Red and Green, balance the difference at the top and
bottom. Too much of an difference at the top or bottom makes
convergence procedures harder to accomplish.
4. Repeat Steps 2 and 3 above for Blue while hiding Red.
5. Recheck all Geometry and Convergence settings (see User’s Guide) and
readjust wherever necessary.
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Horizontal Vertical Deflection PCB - Remove and Replace
The Horizontal/Vertical (H/V) Deflection PCB is located in the upper portion of
the Electronic Module card cage.
Tools Needed:
#1 Pozi-drive Phillips-head screwdriver
Parts Needed:
Horizontal Vertical Deflection PCB p/n 105236
To remove the Horizontal/Vertical (H/V) Deflection PCB:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the rear cover.
4. Disconnect six connectors; J34, J35, J36, J41, J42, and J43 (see Figure
5-15). Move the cables out of the way.
5. Loosen (it is not necessary to remove) the 5 Pozi-drive Phillips-head
screws that secure the Horizontal Vertical Deflection PCB to the
electronic module cage.
6. Remove the Horizontal Vertical Deflection PCB by sliding it toward the
left side of the projector (this is the upward direction if the electronic
module is tilted up) so that the mounting screws clear the access holes.
Then lift the side of the PCB that is nearest the front of the projector first
and angle it upward so that the side closest to the rear clears the lip of the
electronic module frame. Be careful when removing or reinstalling the
PCB to avoid damaging it on the fan screws or cable clamps.
7. Reinstall the Horizontal Vertical Deflection PCB by lowering the side that
is nearest to the rear of the projector in first until it clears the electronic
module edge, then lowering the other side. Carefully fit the board over the
mounting screws and slide the board into position. Tighten the screws and
reconnect the connectors.
5.7
Convergence Deflection PCB
Convergence Deflection PCB - Main Functions
5-28
!
Generation of various waveforms for the horizontal and vertical
deflection.
!
Height control
!
Generation of waveforms for dynamic focus
!
Various geometry correction functions for the horizontal and vertical axes
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!
Convergence output amplifiers for all colors and both horizontal and
vertical axes
!
Convergence enable and raster fill function
!
ILA® assembly driver circuitry with temperature compensation
!
Phase locked loop for ILA® assembly drivers
!
IIC serial bus interface
Convergence Deflection PCB - Inputs
X_RGB_CONV - x-axis Convergence waveform from the System Controller
PCB (the amplitude for full-scale correction is about 1 Vpp).
Y_RGB_CONV - y-axis Convergence waveform from the System Controller
PCB (the amplitude for full-scale correction is about 1 Vpp).
CORR_SYNC - square wave from the System Controller PCB, logic level
synchronization signal for the horizontal axis.
V_DRIVE - square wave from the Raster Timing Generator PCB, logic level
synchronized to vertical sync with four horizontal line duty cycle.
WIDTH_CONTROL - a DC waveform from the Horizontal Vertical Deflection
PCB that controls the image width.
IIC_CLK - IIC clock line.
IIC_DATA - IIC data line.
IIC_SINT - IIC interrupt line.
±15 V - input power from the Low Voltage Power Supply for the analog circuitry.
+5.1 V- input power from the Low Voltage Power Supply for the digital circuitry.
Convergence Deflection PCB - Outputs
RGB_ILA®(pos) - positive outputs to the ILA® for the red, green, and blue ILA®
driver circuitry (about ±12 Vpp).
RGB_ILA®(neg) - negative outputs to the ILA® for the red, green, and blue ILA®
driver circuitry (about ±12 Vpp).
H_PARABOLA - horizontal parabola for dynamic focus section of the High
Voltage Power Supply.
V_PARABOLA - vertical parabola for dynamic focus section of the High Voltage
Power Supply.
V_RAMP - vertical ramp waveform to the Horizontal Vertical Deflection PCB
(about 4 Vpp).
V_PARABOLA - vertical parabola waveform to the Horizontal Vertical
Deflection PCB (about 4 Vpp).
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Figure 5-19 Convergence Deflection PCB I/O Diagram.
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Figure 5-20 Convergence Deflection PCB I/O Diagram.
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Figure 5-21 Physical layout of the Convergence/Deflection PCB.
Convergence Deflection PCB - Operation
The Convergence Deflection PCB performs four main functions. It generates the
vertical deflection sawtooth waveform. It generates the square waves that bias the
three ILA®s. It controls the amplitude of waveforms used for convergence
corrections, and it generates the parabolic waveform used for dynamic focus.
The Convergence Deflection PCB receives the V_DRIVE signal, which is a
sample of the vertical sync, from the Raster Timing Generator PCB. The
Convergence Deflection PCB has a Waveform Generator Section that generates
the vertical deflection sawtooth waveform and outputs the V_RAMP signal that
drives the vertical amplifier on the Horizontal Vertical Deflection PCB. The
vertical amplifier drives the CRT deflection coils for vertical deflection. The
Waveform Generator also generates the parabolic waveforms used for geometry
correction such as bow, pincushion, keystone, and linearity
Each of the ILA®s is biased by a square wave generated by the Waveform
Generator on the Convergence Deflection PCB. Each ILA® is biased separately
through the ILA® Bias command in the Factory Adj. Menu. The commands are
received through the IIC interface. As the square wave that drives the ILA® is
increased, the ILA® becomes more sensitive to the image light that strikes the
photoconductive layer and outputs more light. The command that controls the
frequency of the ILA® bias square wave is referred to as ILA® Sensitivity. It is a
global command for all the ILA®s and is received from the IIC interface.
Attached to the green ILA® mount is a thermistor that senses the temperature of
the ILA®. It sends the Convergence Deflection PCB a signal that adjusts the green
ILA® bias to compensate for temperature variations inside the projector. If the
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temperature of the green ILA® increases, the bias is increased to maintain a
constant ILA® output.
The Convergence Deflection PCB receives commands for x and y-axis
convergence from the System Controller PCB. The Convergence Deflection PCB
has a Convergence Control Section that receives the convergence commands,
waveforms from the Waveform generator, and geometric correction data from the
IIC interface. It amplifies the convergence data and outputs it to the Scan Reversal
PCB.
The Waveform Generator section generates a horizontal and vertical parabolic
waveforms that the High Voltage Power Supply uses for dynamic focus.
Convergence Deflection PCB - Remove and Replace
The Convergence/Deflection PCB is located on the bottom side of the Electronic
Module card cage (see Figure 5-2).
Tools Needed
#0 Pozi-drive Phillips-head screwdriver
Parts Needed
Convergence Deflection PCB p/n 105210
To remove the Convergence/Deflection PCB:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the rear cover.
4. Tilt the Electronic Module up.
5. Disconnect six connectors; J31, J32, J33, J38, J39, and J40 from the
Convergence/Deflection PCB (see Figure 5-21). Move the cables out of
the way.
6. Loosen (it is not necessary to remove) the five Pozi-drive Phillips-head
screws that secure the Convergence Deflection PCB to the Electronics
Module card cage.
7. Remove the Convergence Deflection PCB by sliding it upward so the
mounting screws will clear the access holes, then angle the right side
outward. In order to get the right side of the PCB out, it may be necessary
to first, move the PCB out enough to clear the access holes. Then, angle
the left side out just enough for the top 2 fins of the heat sync to fit over
the Electronics Module frame lip. This will allow a little more clearance
for the right side to be removed. Then, maneuver the right side of the PCB
out.
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8. Reinstall the Convergence/Deflection PCB by lowering the right side in
first until it clears the electronic module edge, then lowering the left side
in.
NOTE: It may be necessary to fit the top 2 fins of the heat sync over the
electronic module frame lip at the left to get enough clearance for the right
side to be installed. Carefully fit the board over the mounting screws and
slide the PCB into position. Tighten the screws and reconnect the
connectors.
5.8
Scan Reversal PCB
Scan Reversal PCB - Main Functions
!
Reverses of scan in both horizontal and vertical axes
!
Outputs deflection waveform to the Deflection Yokes on the CRTs
!
Outputs convergence data to Convergence Yokes on the CRT
!
Horizontal width adjustment for each color (R, G &B)
!
Scan failure detection for (horizontal and vertical) deflection amplifiers
Scan Reversal PCB - Inputs
H_OUT_FLYBACK - output horizontal deflection waveform from the Horizontal
Vertical Deflection PCB (about 800 Vpp).
H_LOCK (pos.) - horizontal interlock for the yoke connectors from the
Horizontal Vertical Deflection PCB (about 5 V when closed, 15 V when open).
H_RGB (pos.) - return of horizontal deflection waveform to the Horizontal
Vertical Deflection PCB.
V_RGB (pos.) - output signals of red, green, and blue from the Vertical Amplifier
of the Horizontal Vertical Deflection PCB (about 40 Vpp).
X_RGB (pos.) - output signals of the red, green, and blue from the Horizontal
Convergence Amplifier for the X-axis from the Convergence Deflection PCB.
Y_RGB (pos.) - output signals of the red, green, and blue from the Horizontal
Convergence Amplifier for the Y-axis from the Convergence Deflection PCB.
±15 V - input power from the Horizontal Vertical Deflection PCB for the analog
circuitry.
+5.1 V - input power from the Horizontal Vertical Deflection PCB for the digital
circuitry.
From Yokes
H_RGB_YOKE (neg.) - bottom of red, green, and blue horizontal deflection
yokes.
V_RGB_YOKE (neg.) - bottom of red, green, and blue vertical deflection yokes.
X_RGB_YOKE (neg.) - bottom of red, green, and blue x-axis convergence yokes.
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Y_RGB_YOKE (neg.) - bottom of red, green, and blue y-axis convergence yokes.
RGB_LOCK (neg.) - interlock for red, green, and blue deflection yokes (5 V
when closed or 0 V when open).
Scan Reversal PCB - Outputs
H_LOCK (neg.) - Horizontal Interlock for the yoke connectors to the Horizontal
Vertical Deflection PCB (about 5 V when closed, 15 V when open).
FRONT/REAR - front or rear projection status line to Horizontal Vertical
Deflection PCB (front = low, rear = high).
FLOOR/CEIL - floor or ceiling status line to the Horizontal Vertical Deflection
PCB (floor = low, ceiling = high).
DEFL_OK - deflection status line from the Horizontal Vertical Deflection PCB
(high (about 2 V) = good, low = no scan).
X_RGB(neg) - current feedback signals of the red, green, and blue Horizontal
Convergence Amplifier for the x-axis to the Convergence Deflection PCB.
Y_RGB (neg.) - current feedback signals of the red, green, and blue Horizontal
Convergence Amplifier for the y-axis to the Convergence Deflection PCB.
To Yokes
H_RGB_YOKE (pos.) - top of red, green, and blue horizontal deflection yokes.
V_RGB_YOKE (pos.) - top of red, green, and blue vertical deflection yokes.
RGB_LOCK (pos.) - interlock for red, green, and blue yokes (5 V when closed or
15 V when open).
X_RGB_YOKE (pos.) - top of red, green, and blue x-axis convergence yokes.
Y_RGB_YOKE (pos.) - top of red, green, and blue y-axis convergence yokes.
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Figure 5-22 Scan Reversal PCB I/O Diagram.
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Figure 5-23 Scan Reversal PCB I/O Diagram for Horizontal Vertical Deflection PCB.
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Figure 5-24 Scan Reversal PCB I/O Diagram for CRT Yokes.
Scan Reversal PCB - Operation
The Scan Reversal PCB has several functions. It provides an interface for scan
reversal, and provides for horizontal width adjustment. The Scan Reversal PCB
outputs the convergence and deflection waveforms that drive the CRT
convergence and deflection yokes, and it contributes significantly to the CRT
Protection circuit.
The Scan Reversal PCB provides an interface for reversing the projection mode
from front to rear projection and from upright to inverted (upside down) mounting
projection setups. The projection modes are changed by switching a jumper from
one connector to another on the Scan Reversal PCB. J100 and J101 are for
horizontal scan connections. J53 and J53A are the vertical scan connections, and
J50 and J50A are convergence jumper connections. The Model 250 comes set for
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front/upright projection. This means the horizontal scan jumper is plugged into
J100, the vertical scan jumper is plugged into J53, and the convergence jumper is
plugged into J50.
NOTE: Whenever the horizontal scan jumper is switched from front projection to
rear projection, the convergence must also be switched from J50 to J50A.
The Scan Reversal PCB sends two signals (FRONT/REAR and
FLOOR/CEILING) back to the Horizontal Vertical Deflection PCB, which sends
the signals back to the System Controller PCB through the IIC data bus. This
allows the System Controller PCB to properly output convergence and shading
data, however the shading, convergence, geometry will need to be adjusted after
switching deflection modes.
The Scan Reversal PCB receives the deflection waveforms from the Horizontal
Vertical Deflection PCB. The horizontal deflection waveforms go through the
horizontal size adjustment inductors (L1, L2, and L3) and is output to the
Deflection Yokes on the CRT without any further signal processing. The vertical
deflection waveforms pass through the Scan Reversal PCB without any further
signal processing. The convergence data passes through the Scan Reversal PCB to
the Convergence Yokes on the CRT without any further signal processing.
The Scan Reversal PCB provides for the adjustment of horizontal scan width.
Inductor L1 adjusts the red horizontal width, and L5 adjusts the blue horizontal
width. L3 increases the horizontal size range of red and blue.
The Scan Reversal PCB contains two major components of the CRT Protection
circuit. The first component is the DEFL_OK signal that goes back to the
Horizontal Vertical Deflection PCB. The Scan Reversal PCB has a sensing
inductor (coil) that detects the presence of a horizontal and vertical deflection
waveform for each CRT. These sense lines combine to drive the DEFL_OK
signal. If any of the deflection waveforms are not present, the DEFL_OK signal
goes low. As the /SWEEP_OK signal it shuts down the G1 and G2 regulator
voltages on the Video Amplifier PCB. It also shuts down the high voltage section
of the High Voltage Power Supply (see CRT Protection section of Ch. 7-Troubleshooting).
The other component of the CRT Protection circuit on the Scan Reversal PCB is
the H_LOCK+ and H-LOCK- signals. These signals are actually one voltage (+15
V) that forms a series circuit through each vertical and horizontal deflection yoke
connector on each CRT. If any of the deflection yokes are not properly or
securely installed, the H_LOCK- signal shuts down the horizontal amplifier on
the Horizontal Vertical Deflection PCB (see CRT Protection section of Ch. 7-Troubleshooting).
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Scan Reversal PCB - Service Adjustments
Figure 5-25 Physical layout of the Scan Reversal PCB.
Horizontal Size adjustment
The Horizontal size adjustment must be performed after the Horizontal Vertical
Deflection PCB is replaced.
Tools Needed
Delrin .100 hex alignment tool
Equipment Needed
No equipment needed
To adjust the horizontal size coils (see Figure 5-25):
4. Remove the rear cover and pull the Interlock switch out to the Service
Mode position.
5. Power ON the projector by IR Remote or PC, and allow it to stabilize for a
minimum of 15 minutes
6. Use the X-hatch test pattern.
7. Hide Blue. View Red and Green.
8. If the Red image is outside the Green image on both sides, or inside the
Green image on both sides, use a Delrin .100 hex alignment tool to adjust
the Red horizontal size coil to correct the error. If the Red image is outside
the Green image on one side and inside of Green on the other side, this is
most likely caused by Red not being centered correctly and can be
corrected with the centering adjustment (User’s Guide, Chapter 5).
If the Red horizontal size coil does not completely eliminate the size error
between Red and Green, balance the difference on both sides to allow for
easier convergence.
9. Repeat Steps 4 and 5 above for Blue while hiding Red.
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10. Recheck all Geometry and Convergence settings and readjust wherever
necessary.
11. Replace the rear cover.
Front/Rear Projection Jumper Settings
In the procedures below each of the jumpers mentioned have a specific purpose:
J100 and J101 are the horizontal scanning jumpers, J 53 and J53A are the vertical
scanning jumpers, and J50 and J50A are the convergence jumpers.
CAUTION! Do not attempt to switch jumpers while the
projector is operating. The projector must be powered OFF when Scan
Reversal Jumpers are being changed.
Front/Rear Jumper Setting (Horizontal Reverse)
!
The Horizontal Scan Reversal Jumper reverses the image projection for
front or rear projection. Figure 5-25 illustrates the jumpers’ location on the
Scan Reversal Board.
!
The Model 250 Projector is shipped with the jumper plugs inserted in J50
and J100 for front/upright projection (see Table 5-1 for other
orientations).
To set the Horizontal Scan Jumper:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically).
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the rear cover.
4. Verify that the Horizontal Scan Reversal jumper is plugged into J100 and
the convergence jumper is plugged into J50 for front projection (see
Figure 5-25 and Table 5-1).
5. Switch the Horizontal Scan Reversal jumper to J101 and the Convergence
Jumper to JA50 for rear projection (see Figure 5-25 and Table 5-1).
6. Replace the projector cover.
7. Power ON the projector and allow it to stabilize for a minimum of 15
minutes. It is recommended that the projector be operating for a least one
hour before performing shading adjustments.
8. Recheck centering, convergence, and shading when changing jumpers for
front or rear screen projection.
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Table 5-1 Projection orientation jumper settings.
Convergence.
P50 goes to:
Vertical.
P53 goes to:
Horizontal.
P100 goes to:
J50
J53
J100
Front/Inverted*
JA50
JA53
J101
Rear/Floor
(Upright)
JA50
J53
J101
J50
JA53
J100
Orientation
Front/Floor
(Upright)
Rear/Inverted*
* see CAUTION! below
NOTE: Whenever the horizontal scan jumper is switched from front projection to
rear projection, the convergence must also be switched from J50 to J50A.
Floor/Ceiling Jumper Setting
The Ceiling/Floor jumpers invert the image vertically for use in some situations
that use dual mirror projection setups.
CAUTION! The Model 250 Projector can not be
mounted in the inverted (upside down) position, however there are
dual mirror applications where the vertical scan jumper will need to be
changed to the inverted setting (JA53).
Figure 5-21 illustrates the location of the jumpers on the Scan Reversal Board.
The Model 250 Projector is shipped in the normal vertical projection position with
the jumper plug inserted into J53. For an inverted vertical setup this jumper plug
must be inserted into JA53. (see Table 5-1 for other orientations).
To invert the vertical image:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the rear cover.
4. Verify that the Vertical Scan Jumper is plugged into J53 for upright
projection. (see Figure 5-25 and Table 5-1).
5. Switch the Vertical Scan Jumper to JA53 for inverted projection. The
Convergence Jumper will not need to be changed for inverted projection
unless the Horizontal Scan Jumper is being changed.
6. Replace the rear cover.
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7. Power ON the projector and allow it to stabilize for a minimum of 15
minutes. It is recommended that the projector be operating for a least one
hour before performing shading adjustments.
8. When changing jumpers for floor or ceiling screen projection, Centering,
Convergence and Shading must be rechecked.
Scan Reversal PCB - Remove and Replace
The Scan Reversal PCB is located on the front side of the Electronic Module (see
Figure 5-2).
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
Parts Needed
Scan Reversal PCB p/n 102585
To remove the Scan Reversal PCB:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the projector rear cover.
4. Disconnect seven connectors (seeFigure 5-25): J52, J54, J64, J65, J66, J50
(or J50A), and J100 (or J101). To remove, push in slightly, squeeze the
tabs, and then pull connector out.
5. Move all cables out of the way.
6. Remove the four Pozi-drive screws (see Figure 5-25) and lift the board off
the Electronics Module.
7. Reinstall in the reverse order from above.
5.9
Video Amplifier PCB
Video Amplifier PCB - Main Functions
!
Amplification of video signals and driving the cathode of all three CRTs
!
Sensing the cathode beam current for all three CRTs
!
G1 regulator for all three CRTs
!
Blanking drive section
!
Phosphor protection for all three CRTs
!
G2 regulator and adjustment of black level (screen) for all CRTs
!
DC restoration for the video signals
!
CRT interface for focus, heater voltage and ARC ground
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Video Amplifier PCB - Inputs
RGB_VIDEO - image pre-amp signals from the Video Processor PCB (about 0.5
Vpp).
RESTORE - image DC restorations pulse from Video Processor PCB, logic level
positive going 4% duty cycle.
BLANKING - Blanking signal, logic F type.
G1_SUPPLY - supply for G1 grid on CRTs from High Voltage Power Supply
(about -150 V).
G1_BIAS - brightness control line from Video Processor PCB (0-5 VDC).
RGB_G2 - G2 (black level) control lines from Video Processor PCB (0-3.1 V).
G2_SUPPLY - supply for G2 grid on CRTs from High Voltage Power Supply
(about 1200 V).
RGB_ FOCUS - Focus supply for CRTs from the High Voltage Power Supply
(approximately 7 kV).
SWEEP_OK - deflection status line from the Horizontal Vertical Deflection PCB.
+80 V - from the Low Voltage Power Supply
±15 V - input power for the analog circuitry from the Low Voltage Power Supply.
6.2 V - input power for the CRT filaments heaters from the Low Voltage Power
Supply.
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Figure 5-26 Video Amplifier PCB I/O Diagram
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Figure 5-27 Video Amplifier PCB I/O Diagram for the Video Processor PCB and
CRTs.
Video Amplifier PCB - Outputs
RGB_BEAM - Cathode beam current sense lines (about 1 V per 100 µA).
RGB_CATHODE - image output signal to CRTs (about 40 Vpp with peak
voltage of 70 V).
RGB_G1 - G1 voltage to CRTs (Blanking pulse to CRT).
RGB_G2 - G2 voltage for CRTs (about 600-800 V).
RGB_HEAT (pos.) - positive side of the CRT heater voltage (about 6.2 V).
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RGB_HEAT (neg.) - negative side of CRT heater voltage (ground level).
ARC_GND - CRT ground back to High Voltage Power Supply (CRT Protection
against arcing).
/VA_OK - CRT Protection signal to the High Voltage Power Supply (low = good,
high = bad). This signal is becomes /HV_ENA at the High Voltage Power Supply.
Video Amplifier PCB - Operation
Image Amplifier
The main function of the Video Amplifier PCB is to amplify each of the image
signals going to the cathode of the CRTs. The Video Amplifier PCB amplifies the
image signal with a gain of approximately 80.The DC Restore from the Video
Processor PCB is added to the amplifier circuit and the image signal is sent to the
CRT. The Video Amplifier PCB uses the +80 V from the Low Voltage Power
Supply to bias the image amplifier circuits.
G1 Regulation and Blanking
The Video Amplifier PCB provides G1 regulation for the blanking pulses. The
Video Amplifier PCB receives the blanking pulse timed to both the horizontal and
vertical syncs from the Raster Timing Generator PCB. It also receives the DC
offset (G1_BIAS) control voltage (0-5 V) that comes from the brightness control
on the Video Processor PCB. The G1_supply (-200 V) comes from the High
Voltage Power Supply. The G1 regulator regulates the -150 V G1 supply up to
about -80 V. The blanking pulse is added to the -80 V and the G1 bias adds an
offset for brightness control. This voltage is distributed to each of the CRT’s G1
control grids.
G2 (Black Level) Voltage
The Video Amplifier PCB receives the G2 supply voltage (1200) from the High
Voltage Power Supply. It receives the G2 control lines from the Video Processor
PCB. The Video Amplifier PCB regulates the G2 supply voltage down to about
1100 V and distributes it to each G2 regulator (one for each CRT). The G2 control
line from the Video Processor PCB controls the output of each G2 regulator
according to the G2 (Black Level) command setting in the Convergence Menu.
The output goes to the G2 grid on the CRT.
CRT Filament (Heater) Voltage
The Video Amplifier PCB receives the Filament (heater) voltage (+6.2 V) from
the Low Voltage Power Supply and distributes it to the filament of each CRT.
The filament or heater heats the cathode and causes it to emit electrons that are
accelerated toward the anode of the CRT to form the image on the face of the
CRT.
CRT Protection Circuit
The Video Amplifier PCB plays a major role in the CRT Protection circuit.
The/SWEEP_OK from the Horizontal Vertical Deflection PCB becomes /VA_OK
on the Video Amplifier PCB. If the /VA_OK goes high, the Video Amplifier PCB
shuts down the G1 and G2 regulators effectively shutting down the all the CRTs.
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The Video Amplifier PCB detects all the necessary supply voltages (+80 V, +15
V, and the +6.2 V) for the CRT and includes that as part of the /VA_OK signal. If
any of the supply voltages is not present, /VA_OK goes high, again shutting down
the G1 and G2 regulators. The /VA_OK goes out to the High Voltage Power
Supply as the /HV_ENA. If the /VA_OK goes high, the /HV_ENA goes high and
shuts down the high voltage amplifier section of the High Voltage Power Supply
(see CRT Protection section of the Ch 7-- Troubleshooting).
The CRT Protection circuit on the Video Amplifier PCB also has a beam current
sense line for each CRT that comes from the output of the image amplifier circuit.
It samples each CRT beam current and sends that back to the Video Processor
PCB. The Video Processor PCB compares the beam current to a reference value
(250 µA). If the beam current of any CRT meets or exceeds that reference value,
the Video Amplifier PCB reduces the Contrast of the CRTs (a global adjustment)
until the beam current is below the reference.
The CRT Protection circuit also provides isolation of the anode voltage return
through the Arc Ground circuit. Occasionally, particles flake off metal
components inside CRTs that cause shorting inside the CRT. On these occasions,
the Arc Ground circuit is an isolated ground path back to the High Voltage Power
Supply. This isolation protects the other supply voltage returns.
The Video Amplifier PCB has three CRT Socket PCBs that are attached to the
back of each CRT. These PCBs provide an interface between the Video Amplifier
PCB and the CRT for the image signal, G1, G2, and filament voltages (see Figure
5-28). The Arc Ground cable is also routed through the CRT Socket PCB. The
Anode cables are routed directly from the High Voltage Power Supply to each
CRT. The red Focus Voltage cables are routed directly to each CRT Socket PCB.
Video Amplifier PCB - Remove and Replace
The Video Amplifier PCB is located under the CRT assemblies at the rear of the
projector.
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
2.5-mm Hex wrench
Parts Needed
Video Amplifier PCB p/n 105232
To remove a Video Amplifier PCB:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove the rear cover.
4. Tilt the Electronic Module up.
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5. Remove the green CRT by loosening the green CRT Holder Ring (see
Figure 5-29). Perform this step with the CRT Socket Connector still
connected to the Green CRT and the ground wire still connected from the
CRT/Yoke Assembly to the CRT Socket Connector. The Green CRT
Socket Connector is close to the rear of the projector. It is easier to
disconnect it from the CRT after the CRT/Yoke Assembly is loose and
moved away from the rear of the projector (see CAUTION below).
NOTE: The holder ring should only be hand-tight. If it cannot be removed
by hand, place a Flathead screwdriver in the slots on the CRT Holder Ring
(see Figure 5-29) and tap lightly to help loosen it. Be careful not to let the
Flathead screwdriver slip out of the slot and possibly damage components.
Do not use a screwdriver or any other tool to tighten this ring. It should be
hand-tight only.
CAUTION! The connections at the rear of the CRT
are very fragile and can be damaged easily. Use extreme care
when removing the CRT/Yoke Assembly to prevent damage to any
CRT connections.
6. Carefully remove the Green CRT/Yoke Assembly by sliding it backward
and upward as far as possible before disconnecting the Green CRT Socket
Connector from the CRT neck. Use care to avoid bumping the CRT while
removing it from the projector, to avoid damaging it. Also, be careful not
to pull any of the wires that connect from the CRT Socket Connector to
the Video Amplifier to avoid damaging them.
7. Move the Green CRT/Yoke Assembly away from the rear of the projector,
then disconnect the Green CRT Socket Connector and the ground wire
between the CRT/Yoke Assembly and the CRT Socket Connector.
NOTE: It may be helpful to perform this step with a partner-one person to
hold the CRT/Yoke Assembly firmly and the other to remove the CRT
Socket Connector and the ground wire.
8. Carefully lay the Green CRT Socket Connector on the top of the Video
Amplifier PCB.
9. Place the Green CRT Assembly in a safe location on or against one of the
other CRT Assemblies.
10. Disconnect the Red and Blue CRT Socket Connectors and carefully lay
them on the top of the Video Amplifier PCB.
11. Disconnect the three connectors (push in slightly, squeeze the tabs, and
pull out), J67, J68, and J69 from the Video Amplifier PCB (see Figure
5-28). Move the cables out of the way.
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12. Disconnect the three Focus cables that run from the CRT Socket
Connectors to the Focus connectors on the HVPS.
NOTE: Observe that each of the three Focus cables (large, red wires that
run from each CRT Socket Connector to the Focus connectors on the
HVPS) is joined near the CRT by a coupler plug and jack. Disconnect
(and label) the focus cables at these couplers.
13. Loosen the six Pozi-drive Phillips-head screws that secure the Video
Amplifier PCB to the projector frame.
14. Make sure everything is out of the way, then slide the Video Amplifier
PCB toward the left so the mounting screws will clear the access holes and
remove the board from the projector.
15. Reinstall in the reverse order from above.
Figure 5-28 Video Amplifier PCB showing CRT Socket Connectors.
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5.10 CRT/Yoke Assemblies
CRT/Yoke Assemblies - Main Function
!
CRTs converts image signal to image light
!
Yokes provide horizontal and vertical deflection for CRTs
!
Yokes provide x-axis and y-axis convergence correction for CRTs
CRT/Yoke Assemblies - Inputs
To Yokes
H_RGB_YOKE (pos.) - top of red, green, and blue horizontal yokes.
V_RGB_YOKE (pos.) - top of red, green, and blue vertical yokes.
RGB_LOCK (pos.) - interlock for red, green, and blue yokes (5 V when closed or
15 V when open).
X_RGB_YOKE (pos.) - top of red, green, and blue X-axis Convergence yokes.
Y_RGB_YOKE (pos.) - top of red, green, and blue Y-axis Convergence yokes.
To CRTs
Anode Voltage from High Voltage Power Supply (25 kV).
Focus Voltage from High Voltage Power Supply (7 kV).
RGB G1 - G1 grid signal from Video Amplifier PCB.
RGB G2 - G2 supply voltage from Video Amplifier PCB (about 600-800 V).
RGB_CATHODE - video output signal from the Video Amplifier PCB (about 40
Vpp with a peak voltage of about 70 V).
RGB_HEAT (pos.) - positive side of CRTs heater voltage (about 6.2 V).
CRT/Yoke Assemblies - Output
From Yokes
H_RGB_YOKE (neg.) - bottom of red, green, and blue horizontal yokes.
V_RGB_YOKE (neg.)- bottom of red, green, and blue vertical yokes.
RGB_LOCK (neg.) - interlock for red, green, and blue yokes (5 V when closed or
0 V when open).
X_RGB_YOKE (neg.) - bottom of red, green, and blue X-axis Convergence
yokes.
Y_RGB_YOKE (neg.) - bottom of red, green, and blue Y-axis Convergence
yokes.
From CRTs
RGB_HEAT (neg.) - negative side of CRTs heater voltage (0 V).
ARC_GND - CRTs ground (Anode supply return line).
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Image - image light that passes through Relay Lens and focuses on photosensitive
layer on input side of ILA®.
CRT/Yoke Assemblies - Operation
The CRTs receive image signals that come from the VICs to the Video Processor
PCB, to the Video Amplifier PCB. The image information drives an electron gun
inside the CRT. The Cathode of the CRT is a small, metal oxide disk that covers
the filament heater. The filament heater heats the Cathode causing it to emit
electrons. The electrons travel forward to the positively charged CRT Anode. As
the electrons travel forward in the CRT, they pass through control grids, each one
more positively charged than the next.
The first grid G1 is a small aperture that is negatively charged with respect to the
Cathode. The negative bias voltage allows the beam current to be controlled by
the video signal applied between G1 and the Cathode to modulate brightness.
The G2 control grid restricts the beam of electrons to a narrow path and
accelerates them because of its positive voltage. The G3 grid works with G2 to
form an electrostatic focusing lens that focuses the electron beam on the CRT
phosphor.
The Deflection Yokes use magnetism to deflect the electron beam horizontally or
vertically inside the CRT. The Deflection Yokes deflect the electron beam at right
angles, so the Horizontal Deflection Yokes are on the top and bottom of the CRT.
The Vertical Deflection Yokes are on the left and right sides. Both the horizontal
and vertical deflection waveforms come from the Horizontal Vertical Deflection
PCB. Geometric, Convergence, and Shading correction information is add to the
deflection waveforms to adjust them so they create a centered, linear uniform
image on the screen.
Each CRT is encased in a metal shroud made of Mu metal. This shroud protects
the CRT from stray magnetism from PCBs, cooling fan motors and the
magnetism from other CRTs. The stray magnetism can influence the CRT Yoke
magnetism causing noise and distortion on the screen.
CRT/Yoke Assemblies - Service Adjustments
NOTE: It is recommended that the CRT Mechanical Focus procedure and the
CRT Rotation procedure be done sequentially. This means that the CRT
Mechanical Focus procedure should be performed immediately followed by the
CRT Rotation procedure or vice versa. The reason for this is there are two
setscrews, one on either side of the Guide Plate, that hold the CRT in position.
Loosening the setscrews to perform one adjustment may cause the other
adjustment to change; therefore, both adjustments should be performed at the
same time.
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CRT Mechanical Focus
The CRT Mechanical focus is factory-set and normally will not require additional
adjustment unless a CRT has been replaced. After replacing a CRT, reset the
mechanical focus. After completing the CRT installation and mechanical focus,
check the other CRTs for convergence and shading.
Tools Needed
1.5-mm Hex-head wrench
#0 Pozi-drive Phillips-head screwdriver
To adjust the CRT Mechanical Focus:
1. Remove the rear cover.
2. Pull the Interlock Switch for the rear cover up to the Service Mode
position.
3. Power the projector ON and allow it to stabilize for at least 15 minutes.
4. Tilt the Electronic Module to the full up position.
5. Select the Focus pattern (test pattern #6).
6. Zoom the Projection Lens to the widest angle (largest image) and adjust
the Projection Lens focus for the sharpest image of the Focus test pattern.
7. Loosen the two setscrews (see Figure 5-29) near the top of the CRT sleeve
using the 1.5-mm Hex-head wrench.
8. Loosen the CRT focus lock screw located on the Guide Plate at the top of
the CRT shield (see Figure 5-29). The CRT is now free to slide.
9. Grasp the CRT thumbscrew (see Figure 5-29) and slide the CRT forward
and backward until the image is focused as sharply as possible (be careful
not to loosen the CRT thumbscrew, which could allow the CRT to rotate).
10. Tighten the setscrews first, then the CRT focus lock screw.
NOTE: Tighten the setscrews before tightening the focus lock screw. If
the setscrews are loose the focus lock screw can slightly defocus or rotate
the CRT as it is being tightened.
11. Repeat the above steps for the Red and Blue CRTs.
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Figure 5-29 CRT Mechanical Focus adjustments.
CRT Rotation
The CRT tilt adjustment aligns the CRT level with the screen. This is a factory-set
adjustment and should not need adjusting unless the CRT or yoke is moved.
Tools Needed
1.5-mm Hex-head wrench
#0 Pozi-drive Phillips-head screwdriver
3-mm Hex-head wrench
To perform the CRT Rotation adjustment:
1. Remove the rear cover.
2. Power the projector ON and allow it to stabilize for at least 15 minutes.
3. Tilt the electronic module to the full up position.
4. Select Center/Lin pattern (test pattern #8).
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5. View the color for the CRT that requires rotation. Hide the other two
colors.
6. In the Geometry menu, set “Reg Enable” to off by unchecking the box.
Unchecking the Reg Enable box temporarily disables any convergence
corrections that have been performed with a different CRT/Yoke assembly
and sets these values to the default levels so that CRT Rotation can be
accomplished correctly.
7. In the Geometry menu, access Bow, Skew, Pincushion, and Keystone
adjustments. Record the values for each setting. After recording the
values, set each adjustment to the default level of 128 so the CRT Rotation
can be performed without the influence of any previous corrections. For
the Skew adjustment, select the color of the CRT that is to be rotated (the
other functions are not color-selectable).
8. Loosen the two setscrews (see Figure 5-29) near the top of the CRT sleeve
using the 1.5-mm Hex-head wrench.
9. Loosen the CRT Thumbscrew (see Figure 5-29) on the top of the CRT
Assembly using the 3-mm Hex-head wrench if necessary.
NOTE: The CRT Thumbscrew is used more as a handle to move the CRT
position as in rotating the CRT or moving the CRT back and forth for
Mechanical Focus. When the positioning is complete, only hand tighten
the CRT Thumbscrew.
10. Rotate the yoke by grasping the Thumbscrew and moving it in whichever
direction is necessary to make the CRT raster square with the screen.
11. When the CRT raster is square on the screen, tighten the two setscrews
first, then the CRT thumbscrew.
12. In the Geometry menu, put a check the Reg Enable box.
13. Reset Bow, Pincushion, Keystone, and Skew (select proper color for
Skew) to the values recorded in Step 4.
14. Recheck Bow, Pincushion, Keystone, and Skew and readjust if necessary.
Also recheck Convergence (see the Setup Adjustments section, Chapter 5
in the Model 250 User’s Guide).
NOTE: If replacing a CRT/Yoke Assembly, the horizontal size coils on
the Scan Reversal PCB may need adjustment to compensate for the new
yokes.
15. Repeat the above procedure for any other CRT that is not level.
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CRT Electronic Focus
The Electronic Focus is factory-set and normally will not need to be adjusted
except after component replacement, maintenance, or if wide temperature
variations exist between the factory and the field location. View one color at a
time.
Tools Needed
Medium Phillips-head screwdriver
To perform the Electronic Focus adjustment:
1. Remove the front and rear cover.
2. Power the projector ON and allow it to stabilize for at least 15 minutes.
3. Select the Focus pattern (test pattern #6).
4. Zoom the Projection Lens to the widest angle and adjust the Projection
Lens focus for the sharpest image.
5. View Green. Hide Red and Blue.
6. Adjust the Green Electronic Focus located on the side of the High Voltage
Power Supply (see Figure 3-5 and 3-6) for a sharp focus of the Focus
pattern at the center of the screen.
7. Repeat the above steps for Red and Blue.
Figure 5-30 View of CRTs, Relay lenses and ILA® Assemblies.
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CRT/Yoke Assemblies - Remove and Replace
Three CRT/Yoke Assemblies are located in the CRT Assembly area below the
card cage (see Figure 5-30).
WARNING!!! Handle the CRT/Yoke Assemblies with
extreme caution. If they are dropped, they can implode and flying glass
can cause severe injury to personnel. Be careful not to bump or drop the
CRT. Immediately after removal, place the CRT/Yoke in a safe area.
Procedure to remove a CRT/Yoke Assembly:
Tools Needed
#0 Pozi-drive Phillips-head screwdriver
Parts Needed
CRT p/n 105199
To remove and replace a CRT:
1. Power OFF the projector by IR Remote or PC, and allow the cooling fans
to run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. Remove front and rear covers.
4. Tilt the Electronic Module up and lock it in place.
5. Loosen the two Pozi-drive Phillips-head screws from the top of the High
Voltage Power Supply cover. Remove the one Pozi-drive Phillips-head
screw at the bottom of the cover.
6. Remove the CRT Anode cable of the CRT being replaced from the High
Voltage Power Supply.
7. Disconnect the Yoke plug and cable harness from the Scan Reversal PCB
for the appropriate CRT (see Figure 5-25).
8. Remove the wires from the cable clamp for the CRT/Yoke Assembly
being removed.
9. Loosen the CRT Holder Ring (knurled knob in Figure 5-29).
NOTE: The CRT Holder Ring should be only hand-tight. If it is not
possible to remove by hand, place a Flathead screwdriver in the slots on
the CRT Holder Ring and tap lightly to help loosen it. Do not use a tool of
any kind to tighten this ring - hand tighten only.
10. Carefully remove the CRT/Yoke Assembly by sliding it backward and
upward as far as possible before unplugging the CRT socket connector
from the neck.
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NOTE: For the Green CRT/Yoke Assembly only, it is best to perform
Step 10 with the CRT socket connector still connected to the Green CRT
and the ground wire still connected from the CRT to the socket connector.
Because the Green CRT socket connector is close to the rear of the
projector, it is easier to disconnect the socket connector from the CRT
after the CRT/Yoke Assembly is loose and moved away from the rear of
the projector. Be careful not to break any of these connections.
CAUTION!
Use extreme caution to avoid bumping
the CRT/Yoke Assembly while removing it (see Warning at the
beginning of this procedure).
11. After removing the CRT/Yoke Assembly, carefully disconnect the CRT
socket connector and the ground wire that connects the CRT to the socket
connector.
NOTE: It may be helpful to have another person assisting for step 9. One
person can disconnect the CRT socket connector and ground wire, while
the other person holds the CRT/Yoke Assembly firmly.
12. After verifying that all cables are out of the way, remove the CRT/Yoke
Assembly from the projector.
13. Reinstall the CRT/Yoke Assembly in the reverse order.
NOTE: When reinstalling the CRT/Yoke Assembly, plug the CRT ground
wire into the CRT Socket Connector first, then partially plug the Green
socket connector into the CRT. Inserting the CRT fully into the socket
connector will be easier when the CRT is completely installed.
14. Perform a CRT Mechanical focus adjustment and CRT Rotation after
replacing the CRT/Yoke Assembly. Because replacing the CRT/Yoke
Assembly can disturb other focus adjustments, check the CRT Mechanical
Focus on the other two colors to verify that they are still correct.
15. Check the on-screen horizontal size and adjust the Horizontal Size
Adjustment Coils on the Scan Reversal PCB if necessary.
5.11 Video Input Cards (VICs)
The VIC is the interface between the input source and the projector. Several input
source format are accepted such as separate RGBHV, Composite, YPbPr, and SVideo.
The Model 250 accepts six different VICs;
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!
Wide Bandwidth RGBHV (Standard)
!
Graphics Enhancer Plus RGBHV(Standard)
!
4-Input (Quad) RGBHV (Optional)
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!
YPbPr (Optional)
!
Quad Standard Decoder (Optional)
!
Quad Standard Decoder/Line Doubler (Optional)
The are three VICs slots on the Model 250, however the 4-Input RGBHV, and the
Quad Standard Decoder/Line Doubler require two slots.
Standard RGBHV VIC
RGBHV VIC - Main Functions
!
Interface for Red, Green, and Blue image inputs
!
Interface for Horizontal and Vertical synchronization pulses
!
IIC Serial Data Bus communication
!
LED indication of VIC selection
Figure 5-31 RGBHV VIC I/O Diagram.
Figure 5-32 RGBHV VIC faceplate.
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RGBHV VIC - Inputs
R - red image from source input (0.7-1.0 Vpp).
G - green image from source input (0.7-1.0 Vpp).
B - blue image from source input (0.7-1.0 Vpp).
H - horizontal sync from source input
V - vertical sync from source input
+15 V - (not used)
-15 V - (not used)
+5.1 V - power for digital circuitry
+5.1 V Stdby (not used)
IIC CLK - IIC clock line
IIC DATA - IIC data line
IIC SINT - IIC interrupt line
RGBHV VIC - Outputs
RED_VIC - red image to the Video Processor PCB (0.7-1.0 Vpp).
GRN_VIC - green image to the Video Processor PCB (0.7-1.0 Vpp).
BLU_VIC - blue image to the Video Processor PCB (0.7-1.0 Vpp).
H_VIC - horizontal sync to the Video Processor PCB
V_VIC - vertical sync to the Video Processor PCB
/SEL_VIC - VIC select line to the Video Processor PCB
RGBHV VIC - Operation
The RGBHV VIC receives the separate red, green, blue image inputs and
horizontal, and vertical sync inputs from the source input device and passes them
directly through to the Video Processor PCB without any signal processing. The
VIC receives a SELECT command from the System Controller PCB through the
IIC data bus to activate the VIC. The VIC sends a /SEL_VIC to an internal Input
Switcher (Mux) on the Video Processor PCB tell it which VIC is selected. An
operator selects the VIC in the Channels Menu (see section 4-6 in the User’s
Guide).
A green LED is illuminated when the VIC is selected.
RGBHV VIC - Service Adjustments
There are no service adjustments on the RGBHV VIC
RGBHV VIC - Remove and Replace
Tools Needed
#0 Posi-drive Phillips-head screwdriver
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Parts Needed
RGBHV VIC p/n 102597
To remove the RGBHV VIC:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. It is not necessary to remove the rear cover.
4. Disconnect the red, green blue, horizontal and vertical input BNC cables
from the VIC.
5. Remove the two retaining screws from the faceplate of the VIC.
6. Pull the VIC out of the Electronics Module.
7.
Reverse the process to install the VIC.
Graphics Enhancer Plus RGBHV VIC
Grahics Enhancer Plus RGBHV VIC - Main Functions
!
Interface for Red, Green, and Blue image inputs
!
Interface for Horizontal and Vertical synchronization pulses
!
IIC Serial Data Bus communication
!
LED indication of VIC selection
!
Graphics Enhancement for black-on-white graphics and text.
Figure 5-33 Graphics Enhancer Plus I/O Diagram.
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Figure 5-34 Graphics Enhancer Plus faceplate.
Graphics Enhancer Plus VIC - Inputs
R - red image from source input (0.7-1.0 Vpp).
G - green image from source input (0.7-1.0 Vpp).
B - blue image from source input (0.7-1.0 Vpp).
H - horizontal sync from source input
V - vertical sync from source input
+15 V - power for analog circuitry
-15 V - power for analog circuitry
+5.1 V - power for digital circuitry
+5.1 V Stdby
IIC CLK - IIC clock line
IIC DATA - IIC data line
IIC SINT - IIC interrupt line
Graphics Enhancer Plus VIC - Outputs
RED_VIC - red image to the Video Processor PCB (0.7-1.0 Vpp).
GRN_VIC - green image to the Video Processor PCB (0.7-1.0 Vpp).
BLU_VIC - blue image to the Video Processor PCB (0.7-1.0 Vpp).
H_VIC - horizontal sync to the Video Processor PCB
V_VIC - vertical sync to the Video Processor PCB
/SEL_VIC - VIC select line to the Video Processor PCB
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Graphics Enhancer Plus VIC - Operation
The RGBHV VIC receives the separate red, green, blue image inputs and
horizontal, and vertical sync inputs from the source input device. The image
signals go to a image enhancement signal processor that peaks the black details,
enhances white details, and minimizes white overshoot according to commands
received from the IIC data bus from the System Controller PCB. The commands
are generated by an operator through the Black Enhance and White Enhance
commands in the Picture Menu. The graphics enhancements are for black text and
graphics on a white background.
The processed red, green, and blue image signals are sent to the Video Processor
PCB. The horizontal and vertical sync pulses go straight through the VIC to the
Video Processor PCB without modification.
The VIC receives a SELECT command from the System Controller PCB through
the IIC data bus to activate the VIC. The VIC sends a /SEL_VIC signal to an
internal Input Switcher (Mux) on the Video Processor PCB. This tell the Video
Processor PCB which VIC is selected. An operator selects the VIC in the
Channels Menu (see section 4-6 in the User’s Guide).
A green LED is illuminated when the VIC is selected.
Graphics Enhancer Plus VIC - Service Adjustments
There are no physical service adjustments on the Graphics Enhancer Plus VIC
Graphics Enhancer Plus VIC - Remove and Replace
Tools Needed
#0 Posi-drive Phillips-head screwdriver
Parts Needed
Graphics Enhancer Plus VIC p/n 106183
To remove the RGBHV VIC:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. It is not necessary to remove the rear cover.
4. Disconnect the red, green blue, horizontal and vertical input BNC cables
from the VIC.
5. Remove the two retaining screws from the faceplate of the VIC.
6. Pull the VIC out of the Electronics Module.
7. Reverse the process to install the VIC.
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4-Input (Quad) RGBHV VIC
4-Input (Quad) RGBHV VIC - Main Functions
!
Interface for four sets of Red, Green, and Blue image inputs
!
Interface for four sets of Horizontal and Vertical synchronization pulses
!
VIC selection by IIC Serial Data Bus
!
LED indication of VIC selection
Figure 5-35 4-Input (Quad) RGBHV VIC faceplate (two VIC slots ).
4-Input (Quad) RGBHV VIC - Inputs
Four sets of inputs
R - red image from source input (0.7-1.0 Vpp).
G - green image from source input (0.7-1.0 Vpp).
B - blue image from source input (0.7-1.0 Vpp).
H - horizontal sync from source input
V - vertical sync from source input
+15 V - power for analog circuitry
-15 V - power for analog circuitry
+5.1 V - power for digital circuitry
+5.1 V Stdby
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IIC CLK - IIC clock line
IIC DATA - IIC data line
IIC SINT - IIC interrupt line
Figure 5-36 4-Input (Quad) RGBHV VIC.
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4-Input (Quad) RGBHV VIC - Outputs
RED_VIC - red image to the Video Processor PCB (0.7-1.0 Vpp).
GRN_VIC - green image to the Video Processor PCB (0.7-1.0 Vpp).
BLU_VIC - blue image to the Video Processor PCB (0.7-1.0 Vpp).
H_VIC - horizontal sync to the Video Processor PCB
V_VIC - vertical sync to the Video Processor PCB
/SEL_VIC - VIC select line to the Video Processor PCB
4-Input (Quad) RGBHV VIC - Operation
The 4-Input (Quad) RGBHV VIC accepts four sets of RGBHV inputs. It has a
Multiplexer (switcher) that selects one set of RGBHV inputs at a time. The VIC
receives a SELECT command from the System Controller PCB through the IIC
data bus to activate the VIC and select an input. The VIC sends a /SEL_VIC
signal to an internal Input Switcher (Mux) on the Video Processor PCB. This tells
the Video Processor PCB which VIC is selected and which set of inputs is
selected. An operator selects the VIC and input in the Channels Menu (see section
4-6 in the User’s Guide).
A green LED illuminates when the VIC is selected.
The 4-Input (Quad) RGBHV VIC uses two VIC slots.
4-Input (Quad) RGBHV VIC - Service Adjustments
There are no service adjustments on the RGBHV VIC
4-Input (Quad) RGBHV VIC - Remove and Replace
Tools Needed
#0 Posi-drive Phillips-head screwdriver
Parts Needed
4-Input (Quad) RGBHV VIC p/n 103668
To remove the RGBHV VIC:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. It is not necessary to remove the rear cover.
4. Disconnect the all the red, green blue, horizontal and vertical input BNC
cables from the VIC.
5. Remove the four retaining screws from the faceplate of the VIC.
6. Pull the VIC out of the Electronics Module.
7. Reverse the process to install the VIC.
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YPbPr VIC
This decoder video input card (YPbPr_VIC) contains three BNC input connectors
that can be used for two different inputs, YPbPr or GBR. The YPbPr PCB
converts these component signals to RGB type image signals.
YPbPr VIC - Main Functions
!
Image input and output buffers
!
Conversion of YPbPr signal format to RGB signals format
!
Separation of syncs from the Y/G input signal
!
Hue, sharpness, gamma, and color adjustment
!
Selection of RGB component input or YPbPr input
!
LED indication
!
IIC serial bus interface
Figure 5-37 YPbPr VIC I/O Diagram.
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Figure 5-38 YPbPr VIC faceplate.
YPbPr VIC - Inputs
YPbPr Inputs
Y - green image input with composite horizontal and vertical sync (0.7-1 Vpp)
Pb - blue image input for YPbPr (0.7-1 Vpp)
Pr - red image input for YPbPr (0.7-1 Vpp)
GBR Inputs
Grn - green image input with composite horizontal and vertical sync (0.7-1 Vpp)
Blu - blue image input (0.7-1 Vpp)
Red - red image input (0.7-1 Vpp)
+15 V - power for analog circuitry
-15 V - power for analog circuitry
+5.1 V - power for digital circuitry
+5.1 V Stdby (not used)
IIC CLK - IIC clock line
IIC DATA - IIC data line
IIC SINT - IIC interrupt line
YPbPr VIC - Outputs
RED_VIC - red image to Video Processor PCB (0.7-1.0 Vpp).
GRN_VIC - green image to signal Video Processor PCB (0.7-1.0 Vpp).
BLU_VIC - blue image to Video Processor PCB (0.7-1.0 Vpp).
SYNC - composite horizontal and vertical sync to Video Processor PCB.
/SEL_VIC - VIC select line to Video Processor PCB.
YPbPr VIC - Operation
This VIC accepts two input signal formats, YPbPr and GBR signals. The YPbPr
VIC converts either input signal format to the RGB format. The selection of the
VIC and inputs is controlled by the System Controller Board via the IIC serial bus
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interface. An operator selects the VIC and input in the Channels Menu (see
section 4-6 in the User’s Guide).
The YPbPr VIC strips the sync pulses that are combined with the green image
signal (Y in YPbPr mode) and sends them to the Video Processor PCB as a
composite sync signal (H_SYNC). The Video Processor PCB separates the
composite sync signal and sends it to the Raster Timing Generator PCB.
The YPbPr VIC also does signal processing in the YPbPr mode with the Tint,
Color, and Sharpness options in the Picture Menu. The Tint control adjusts the
tint of the colors displayed. Facial tones will vary from slightly green at zero to
slightly red at 255. The Color control adjusts the amount of color saturation or
color intensity. Colors will be almost grayscale at zero and very saturated at 255.
The Sharpness control adjusts the high frequency peaking of the black and white
details. These options are not available and are disabled in the RGB mode.
The YPbPr VIC has two LEDs. The RGB LED illuminates green when the
YPbPr_VIC is in RGB input mode. The YPbPr LED illuminates green when the
YPbPr_VIC is in YPbPr input mode. Only one LED will be illuminated at one
time. Neither LED is illuminated when the YPbPr_VIC is not selected as the input
to projector.
YPbPr VIC - Service Adjustments
There are no physical service adjustments to the YPbPr VIC
YPbPr VIC - Remove and Replace
Tools Needed
#0 Pozi-drive Phillips-head screwdriver
Parts Needed
YPbPr VIC p/n 106340
To remove the YPbPr VIC:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. It is not necessary to remove the rear cover.
4. Disconnect the input BNC cables from the VIC.
5. Remove the two retaining screws from the faceplate of the VIC.
6. Pull the VIC out of the Electronics Module.
7. Reverse the process to install the VIC.
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Quad Standard Decoder VIC
The Quad Standard Decoder VIC provides an interface for composite and
S-Video formats input. It contains three BNC input connectors, one for
Composite Video and two for S-Video (luminance and chrominance). This
decoder VIC converts Composite and S-image formats to RGBHV format.
Quad Standard Decoder VIC - Main Functions
!
Select input source, Composite or S-video
!
Select standard-AUTO/NTSC/PAL/SECAM/4.43NTSC
!
Conversion of composite and S-image signals to RGB image signals
!
Separation of syncs from the input signal
!
Tint, sharpness, and color adjustment
!
LED indication of Composite or S-video
!
IIC serial bus interface
Figure 5-39 Quad Standard Decoder VIC faceplate.
Figure 5-40 Quad Standard Decoder I/O Diagram.
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Quad Standard Decoder VIC - Inputs
Comp - input for Composite image signal includes sync pulses (.07-1 Vpp)
Yin - input for Luminance or brightness information of S-image (0.7-1 Vpp)
Cin - input for Chrominance or color information of S-image (0.3-0.6 Vpp)
+15 V - power for analog circuitry
+5.1 V - power for digital circuitry
IIC CLK - IIC clock line
IIC DATA - IIC data line
IIC SINT - IIC interrupt line
Quad Standard Decoder VIC - Outputs
RED_VIC - red image to Video Processor PCB (0.7-1.0 Vpp).
GRN_VIC - green image to signal Video Processor PCB (0.7-1.0 Vpp).
BLU_VIC - blue image to Video Processor PCB (0.7-1.0 Vpp).
SYNC - composite horizontal and vertical sync to Video Processor PCB.
/SEL_VIC - VIC select line to Video Processor PCB.
Quad Standard Decoder VIC - Operation
The Quad Standard Decoder VIC accepts two source input formats, Composite
and S-image. The Composite format combines the image (red, green, and blue)
signals and the sync pulses (horizontal and vertical) into one signal. The S-image
signal has two separate inputs, one contains the color information (Cin), and the
other input contains the black and white information (Yin). The sync pulses are
combined with the Yin. Both the Composite and S-image formats may be in a
variety of different signal standards such as NTSC (U.S.), PAL (European),
SECAM, or 4.43 NTSC. The VIC accepts all of these standards. The Quad
Standard Decoder VIC converts Composite and S-image to the RGBHV format.
The selection of the VIC and inputs is controlled by the System Controller Board
via the IIC serial bus interface. An operator selects the VIC and input in the
Channels Menu (see section 4-6 in the User’s Guide).
The Quad Standard Decoder VIC strips the sync pulses that are combined with
the black and white information (Yin) and sends them to the Video Processor
PCB as a composite sync signal. The Video Processor PCB separates the
composite sync signal and sends it to the Raster Timing Generator PCB.
The Quad Standard Decoder VIC also does signal processing with the Tint, Color,
and Sharpness options in the Picture Menu. The Tint control adjusts the tint of the
colors displayed. Facial tones will vary from slightly green at zero to slightly red
at 255. The Color control adjusts the amount of color saturation or color intensity.
Colors will be almost grayscale at zero and very saturated at 255. The Sharpness
control adjusts the high frequency peaking of the black and white details.
The Quad Standard Decoder VIC has two LEDs. The Composite LED illuminates
green when the Composite input is selected. The S-image LED illuminates green
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when the S-image input is selected. Only one LED will be illuminated at one
time. Neither LEDs will be illuminated when the Quad Standard Decoder VIC is
not selected as the input to projector.
Quad Standard Decoder VIC - Service Adjustments
There are no physical service adjustments to the Quad Standard Decoder VIC.
Quad Standard Decoder VIC - Remove and Replace
Tools Needed
#0 Pozi-drive Phillips-head screwdriver
Parts Needed
Quad Standard Decoder VIC p/n 103545
To remove the Quad Standard Decoder VIC:
1. Power off the projector by IR Remote or PC, and allow the cooling fans to
run until they shut off automatically.
2. Turn the AC Circuit Breaker to the OFF position and unplug the AC
Power Cord.
3. It is not necessary to remove the rear cover.
4. Disconnect the input BNC cables from the VIC.
5. Remove the two retaining screws from the faceplate of the VIC.
6. Pull the VIC out of the Electronics Module.
7. Reverse the process to install the VIC.
Quad Standard Decoder/Line Doubler VIC
The Quad Standard Decoder/Line Doubler VIC is very similar in function to the
Quad Standard Decoder VIC. It accepts the same two source input formats,
Composite and S-image and processes them exactly the same. It has two LEDs
that function exactly as the Quad Standard Decoder VIC. The inputs, outputs and
signal processing are also the same. Selecting the VIC is done in the Channels
Menu, the same as the other VICs. There are two distinguishing differences. The
Quad Standard Decoder/Line Doubler VIC doubles the horizontal scan frequency
of the input source. The other difference is that the Quad Standard Decoder/Line
Doubler VIC takes up two VIC slots.
The Line Doubler section doubles the horizontal scan frequency of the input
source. As an example, if the input source is a Composite signal in NTSC, which
has a line rate of about 15 .75 kHz, the Quad Standard Decoder/Line Doubler VIC
doubles the line rate to 31.5 kHz. This provides a much cleaner display on the
screen.
The Quad Standard Decoder/Line Doubler VIC takes two VIC slots, even though
the faceplate only covers on space. Some of the components prevent it from
fitting into one VIC slot. When the Quad Standard Decoder/Line Doubler VIC is
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installed in the #2 or 3 VIC slot (it will not fit into the #1 slot), a blank face plate
must be installed above it. The blank faceplate is not included with the Quad
Standard Decoder/Line Doubler VIC unless it is installed at the factory. The part
number for the blank faceplate is p/n 102667.
Figure 5-41 Quad Standard Decoder/Line Doubler VIC faceplate with blank
faceplate above it.
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5.12 Backplane PCB
The Backplane PCB is the spine of the Electronics Module. Every major
electronic component in the Model 250 projector connects to and through the
Backplane PCB. It is hidden in the inside of the Electronics Module (see Figure
5-2). The System Controller PCB, Raster Timing Generator PCB, Video
Processor PCB and the three VICs are connected into it directly. All the other
PCBs and Power Supplies are connected through jumpers and cabling.
Troubleshooting on the Backplane PCB
The connectors on the Backplane PCB provide one of the more accessible places
to probe voltages and signals that may be useful for troubleshooting purposes (see
Figure 5-43 and associated list of signals and voltages).
Figure 5-42 Backplane Diagram (left side).
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Figure 5-43 Backplane Diagram (middle section).
The following is a list of pins that would be helpful for troubleshooting purposes.
Low Voltage Power Supply (J8)
High Voltage Power Supply (J7)
Pin #
8
9
10
11
12
13
14
15
16
17
18
1-7
Signal or Voltage
/LV_ENA
/LV_OK
+24 V_FANS
_5.1 V Stdby
+5.1 V
+6.2 V
+15 V
-15 V
+80 V
/COVER_ON
/FAN_ENA
GND
Pin #
5
8
9
10
11
12
1-4
Arc Lamp Power Supply (9)
(28)
Pin #
2
3
4
5
1, 6
(see Figure 5-44)
Pin #
Signal or Voltage
1
+5.1 V Stdby
2
GND
3
/COVER_ON
Signal or Voltage
/LAMP_LIT
/LAMP_OK
/LAMP_ENA
/COVER_ON
GND
Model 250 Service Manual
Signal or Voltage
/HV_OK
+80 V
+15 V
-15 V
G1 SUPPLY
/VA_OK
GND
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Figure 5-44 Backplane Diagram (right side).
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Chapter 6---Miscellaneous Items
6.0 Miscellaneous Items
Contents
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.1
Projector Covers........................................................................................... 6-1
Electronics Module Tilt-up .......................................................................... 6-2
Ventilation.................................................................................................... 6-3
Air Filters ..................................................................................................... 6-4
IR Detectors.................................................................................................. 6-4
EMI Shield ................................................................................................... 6-4
Cleaning Lenses, ILA® Assemblies, and Mirrors ........................................ 6-5
Projector Covers
There are two projector covers, one that covers the front of the projector and one
that covers the rear. The are attached and hinged to the Cross-Member Assembly.
The covers can be tilted up (see CAUTION below) or removed from the projector
to perform service procedures. The projector covers provide a stylish, professional
appearance to the projector, however they also protect operators from exposure to
high voltages and very bright light. Review the Safety chapter and adhere to all
warnings and cautions.
CAUTION!
Do not leave either cover in the tilted up
position! The covers can fall from this tilted up position and possibly
damage projector components. Remove the cover and set it aside when
servicing the projector.
Tools Needed
#1 Pozi-drive Phillips-head screwdriver
To remove the front or rear covers:
1. Disconnect the projector power plug.
2. Loosen the two Pozi-drive Phillips-head spring screws at the front of the
front cover or the rear of the rear cover.
3. Tilt up the front or rear cover.
4. Release the two Latch Levers on the Cross-member assembly that hold the
cover in place. Place the ends of the Latch Levers into the holding slots.
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5. When the Latch Levers are inserted into the holding slots, lift the cover
off. Be careful not to brush against any of the internal components of the
projector when removing the cover. If any undue resistance is felt, stop to
locate the source before proceeding.
6. Replace the covers in reverse order. When replacing either cover, make
sure the slot in the cover fits over the bottom of the projector case or the
cover will not close correctly.
6.2
Electronics Module Tilt-up
The Electronics Module contains all the electronic Printed Circuit Boards for the
Module 250 Projector except for the Video Amplifier PCB and its three
associated CRT socket PCBs. It is located in the rear of the projector. The
Electronics Module can be tilted to a 45° or 90° angle to access and perform
service procedures on ILA®s, CRTs or the Video Amplifier PCB.
To tilt the Electronics Module up:
1. Remove the rear cover.
2. Unlatch the Electronics Module (see Figure 6-1)
3. The locking pin secures the Electronics Module in place at 0°, 45° or 90°
rotation with the locking pin. The Electronics Module locking pin is
located on the rear Electronics Module hinge on the right side of the
Electronics Module.
4. Pull the locking pin out.
5. Lift the left side of the Electronics Module up while continuing to hold the
locking pin out.
6. Release the locking pin when the Electronics Module is in the desired
position and ensure that it snaps into place.
7. Reverse process to tilt Electronics Module down.
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Chapter 6---Miscellaneous Items
Figure 6-1 Electronics Module hinge and locking mechanism.
6.3
Ventilation
Adequate cooling is a major consideration for the Model 250 projector. There are
thirteen cooling fans (including the Arc Lamp blower) in this projector.
!
!
!
!
4 fans in the main chassis - two in the rear of the projector, one in the right
front corner and one on the bottom of the projector. These fans bring cool
air into the chassis of the projector. Each of these fans has an air filter in
front of it.
3 fans in the Electronics Module - two smaller fans force cool air across
the Horizontal Vertical Deflection PCB on the top of the Electronics
Module and one large fan forces cool air into the body of the Electronic
Module
3 fans in the Optics Module - one fan draws hot air from the #1 Cold
Mirror, the other two fans draw hot air off of the Prism Assembly.
3 fans for the Arc Lamp Module - one large fan is mounted on the door of
the Arc Lamp housing, with one smaller fan mounted on the top. The large
blower is on the side of the Arc Lamp housing. All of these fans force cool
air in to cool the Arc Lamp.
All cooling fans are powered by +24 V from the Low Voltage Power Supply
except the large blower for the Arc Lamp. The large blower is powered by AC
power that is switched on and off by a relay switch. The relay switch is powered
by +24 V so effectively, the +24 V turns on all the cooling fans. The cooling fans
turn on as soon as the AC Circuit Breaker is powered ON.
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6.4
Air Filters
There are three polyurethane air filters in the Model 250. Air filters should be
cleaned whenever necessary. In extremely dusty or dirty conditions, the filters
should be cleaned more frequently. Remove the filters and vacuum them or blow
them clean with compressed air.
The air filters just slide out. No tools are required to remove and reinstall any of
the air filters. They are located as follows:
6.5
!
1 metal-framed filter in the rear of the projector in the bottom coveraccessible when the rear cover is off.
!
1 filter on the bottom of the projector-slides out from the middle-left side
of the projector (grasp the hole in the filter frame). The filter can be peeled
off the Velcro on the frame, if necessary.
!
1 metal-framed filter in the front-left-bottom cover accessible with the
front cover off.
IR Detectors
The IR Detectors receive command signals from the IR Remote Control. The
Model 250 projector has two IR Detectors, one on the front of the projector and
one on the rear (mounted on the System Controller PCB). The command signals
go to the System Controller PCB where they are distributed to the various PCBs,
typically by way of the IIC data bus. The IR Detectors can receive commands
from an IR Remote Control from a range of about 45-ft. line of sight.
6.6
EMI Filter
Figure 6-2 EMI Shield with Low Voltage Power Supply and Arc Lamp Power
Supply behind it
The purpose of the Electro-Magnetic Interference (EMI) Shield is to trap and
collect electromagnetic radiated fields generated by switching power supplies.
Switching power supplies radiate high frequency noise that may interfere with
radios, televisions, and other electronic appliances. The EMI Shield is constructed
of a special Mu metal that acts as an antenna to collect and ground the high
frequency noise as required by the Federal Communications Commission and
various other regulatory agencies.
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The EMI Shield is a metal plate located in front of the Low Voltage Power
Supply and the Arc Lamp Power Supply. It must be removed before removing
either of these power supplies. Be sure to replace the EMI Shield after replacing
either the Low Voltage Power Supply or the Low Voltage Power Supply.
6.7
Cleaning Lenses, ILA® Assemblies and Mirrors
The projection lens is the only item that requires periodic cleaning. Other
assemblies are covered to prevent dust entering or finger smudging. Cleaning may
be needed for special circumstances such as replacing an assembly. Cleaning
should only require removing excessive dust (use canned air such as “Office
Duster” or "Aero Duster") or removing fingerprint smudges (use “Kodak Lens
paper”, or equivalent) from the projection lens. As much as possible, clean the
optics only when absolutely necessary.
Projection Lens - Use lens paper and wipe the lens clean in a vertical motion from
top to bottom. Use compressed air to blow excess dust from the lens. An optical
lens cleaning solution can also be used to remove finger smudges.
ILA® Assembly - Clean the ILA® assembly faces with compressed air only. Do
not wipe the ILA assembly faces.
CRT Faces - Use compressed air to blow dust off and lens paper to clean face.
Relay Lens - Same as Projection Lens.
Mirrors and Polarizing Beam Splitter Windows - The Optical Shields cover the
Dichroic Mirror Assembly and Polarizing Beam Splitter windows. Normally
cleaning is not needed. Clean only if absolutely necessary using compressed air.
Do not wipe mirrors.
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Chapter 7---Troubleshooting
7.0 Troubleshooting
Contents
7.1 Safety............................................................................................................ 7-1
7.2 LEDs............................................................................................................. 7-2
Backpanel LEDs......................................................................................... 7-2
Video Processor PCB LEDs....................................................................... 7-5
Raster Timing Generator PCB LEDs ......................................................... 7-7
Convergence Deflection PCB LEDs .......................................................... 7-9
Video Amplifier PCB LEDs ...................................................................... 7-10
Backplane PCB LEDs ................................................................................ 7-11
7.3 Diagrams ...................................................................................................... 7-12
Image Path.................................................................................................. 7-14
Deflection Path........................................................................................... 7-15
CRT Protection........................................................................................... 7-19
7.4 Error Codes .................................................................................................. 7-22
7.5 Troubleshooting Guide................................................................................. 7-25
Troubleshooting on the Backplane PCB .................................................... 7-26
7.1 Safety
CAUTION! Before performing procedures in this chapter,
review the chapter on Safety at the beginning of this manual.
WARNING!!!
When performing troubleshooting
procedures that require projector covers to be off, wear high voltage
gloves (ANSI/ASTM 10,000 volt rated) when working near the CRTs,
Arc Lamp, or power supplies. Wear safety goggles (rated X5) when
working anywhere near the light path from the arc lamp or the
projection lens.
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Left/Right Orientation: When referring to the left or right in this chapter, it is
with reference to standing at the rear of the projector, facing the screen.
Connectors on subassemblies and PCBs have tabs that must be released first
before pulling on the connector. The proper procedure is to push slightly IN on
the connector, then squeeze the tab, then pull the connector out.
7.2 LEDs
Backpanel LEDs
This section covers the various terminals, detectors, and LEDs visible from the
rear and left side of the projector with the rear projector cover and rear panel
removed.
Operation Status LED - This LED indicates the status of the projector. When the
LED is illuminated green, the projector is operating normally. When the LED is
illuminated orange, the projector is in standby mode, which means that the
projector has AC power but has not yet received a POWER ON command. If the
LED is illuminated flashing red, the projector has experienced an error and will
display an error code (see Table 7-1 and Table 7-2).
Service Mode Switch - The Service Mode Switch is used when updating software
to the CPU. The projector must POWERED OFF and the AC Circuit Breaker
must be cycled off. The Service Mode Switch is pushed while turning the AC
Circuit Breaker ON. This starts the projector in the Service Mode. The Software
Update section (see Software Updating, section 8.1) contains the full procedure
for updating CPU software.
Terminal In - The Terminal In is a RS232 port used to communicate with the
projector or Import/Export setup data using a PC or Laptop computer, a switching
device such as a Crestron Control Switcher, or the optional Tethered Technician
Remote Control.
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Figure 7-1 Rear Panel layout
Control Out - The Control Out terminal is another RS232 port similar to the
Terminal In port except that it can not be used to Import/Export setup data.
Tethered Remote Jack - The Model 250 projector is shipped with an IR Remote
Control. This IR Remote can be used with an optional 150 ft. cable that will plug
in the Tethered Remote Jack.
IR Detector - This sensor detects commands from the IR Remote Control included
with the projector. There is another IR Detector on the front of the projector.
Switch Block - The Switch Block controls various parameters of the CPU. Most
of the switches are for diagnostic functions performed at the factory and will not
need to be changed. They should all be in the DOWN position. The switch that
will be of most concern to the field technician is the #4 switch that controls the
baud rate of importing and exporting data and software. The UP position sets the
baud rate at 19200 BPS and the DOWN position is 9600 BPS. 9600 BPS
(DOWN) is the factory default setting.
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Figure 7-2 Dip Switch Block on System Controller PCB.
Reset Switch - The Reset Switch resets the CPU if the projector locks up and does
not respond to an IR Remote, PC or Laptop computer. If the rear panel is in place,
the CPU can also be reset by cycling the AC Circuit Breaker off and back on
again.
CAUTION!
If the Arc Lamp was operating or recently
turned off (the cooling fans were still running) at the time the CPU
locked up, it is very important to turn the AC Circuit Breaker back on
immediately to power ON the cooling fans. The cooling fans are
needed to cool down the Arc Lamp, Optics and PCBs properly to avoid
damage to optical and electronic components.
If the Reset Switch is used, the cooling fans will stop momentarily and
begin operating again automatically.
Figure 7-3 LEDs visible from the left side of the Electronics Module.
For a complete description on each of the LEDs, check the individual PCBs LEDs
in this section.
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Chapter 7---Troubleshooting
Video Processor PCB LEDs
Figure 7-4 Video Processor Test Points and LEDs.
Video Processor - Test Points
The test points on the Video Processor PCB are visible and accessible from the
left side of the Electronics Module when the rear projector cover is removed. The
test points can be grouped into four categories:
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Chapter 7---Troubleshooting
Sync - There are three sync test points: H sync for the horizontal sync pulse, V
sync for the vertical sync pulse, and G sync, which is a combination of the
horizontal and vertical sync pulses that are carried with the green image signal.
External - There are three external image test points: R ext, for the red external
image signal, G ext for the green external image signal, and B ext for the blue
external image signal. The external signal is the image signal coming into the
Video Processor PCB from the VIC.
Figure 7-5 Grey/Pluge (test pattern #7) with associated waveform.
Video - There are three video test points: R video for the red output image signal,
G video for the green output image signal, and B video for the blue output image
signal. The video signal is the image signal leaving the Video Processor PCB and
going to the Video Amplifier PCB.
Ground - The Gnd test point is for reference ground.
The other test point on the Video Processor PCB is for the /Clamp signal, which is
not very useful for troubleshooting purposes.
Video Processor - LEDs
The Video Processor PCB has two green LEDs. VP_OK is a status line that
indicates that the Video Processor PCB is has power (±15 V). The Beam current
LED will be illuminated orange if any of the CRTs is at or exceeding beam
current limit (250 µA). If any of the CRTs is at the beam current limit, the Video
Processor will reduce Contrast. If reducing Contrast does not bring down the
beam current for that CRT, the Video Processor PCB will reduce G2 voltage.
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Raster Timing Generator PCB LEDs
Figure 7-6 Raster Timing Generator LEDs.
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Chapter 7---Troubleshooting
Raster Timing Generator PCB LEDs
Band LEDs
The range horizontal scan frequencies accepted by the Model 250 projector is
divided into four “bands”. The four LEDs (A, B, C, & D) toward the front of the
projector on the Raster Timing Generator PCB indicate which range of horizontal
scan frequencies the input source is operating. The four bands of horizontal
frequencies are
Band A = 15-25 kHz
Band B = 26-29 kHz
Band C = 29-56 kHz
Band D = 56-90 kHz
Only one of these LEDs will be illuminated green at one time. As an example, if
the input source horizontal scan frequency is 64 kHz, Band D LED would be
illuminated green.
Sync Type LEDs
The five LEDs, toward the rear of the projector on the Raster Timing Generator
PCB, indicate the sync of the input source. As an example, the SEP LED would
be illuminated green if the input source had separate horizontal and vertical syncs.
The following list gives a brief description of the each LED and its associated
sync type.
SEP - Separate horizontal and vertical sync inputs.
COMP -Composite (Red, Green, Blue, Horizontal, and Vertical signals all
combined into one signal).
INT - Internal sync means there is no input source sync signal present so the
System Controller PCB generates an internal sync at a horizontal scan rate of
33.7 kHz and a vertical rate of 59.7 Hz interlaced.
GRN - Sync-on-Green sync is where the horizontal and vertical sync signals are
combined with the green image signal.
PLL - Phase Locked Loop is the circuitry that locks onto the horizontal sync. This
LED indicates that the projector has locked onto the horizontal sync signal.
One of the first four LEDs should be illuminated indicating the type of sync used
by the input source. The fifth LED (PLL) should always be illuminated when the
projector is operating except during input source changes.
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Convergence Deflection PCB LED
Figure 7-7 Convergence Deflection PCB LED.
The Convergence Deflection PCB has only one LED. It illuminates green when
power (±15 V) is present on the PCB.
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Chapter 7---Troubleshooting
Video Amplifier PCB LED
Figure 7-8 Video Amplifier PCB LED.
The VA_OK LED on the Video Amplifier PCB is illuminated green when all the
CRT deflection circuits are operating properly (/DEFL_OK), the supply voltages
(±15 V, +6.2 V, and +80 V) are present at the Video Amplifier PCB, and all the
CRT Yoke connectors are properly installed (see Figure 7-15 and Figure 7-16).
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Backplane PCB LEDs
Figure 7-9 Backplane PCB LEDs on right side (exposed side)of PCB.
The Backplane has two status LEDs, the /LV_OK signal from the Low Voltage
Power Supply, and the /HV_OK signal from the High Voltage Power Supply. The
Backplane also has several connectors that can be used for probing signals and
voltages (see Figure 7-18 and associated signals and voltages).
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Chapter 7---Troubleshooting
7.3 Diagrams
Command ON Timing
Figure 7-10 POWER ON and POWER OFF command timing diagram.
When the AC Circuit Breaker is powered ON, the Low Voltage Power Supply
generates a +5.1 V Standby voltage that goes to the System Controller PCB to
power the CPU and IR Detectors. The Low Voltage Power Supply also puts out
the +24 V Standby voltage (/FAN_ENA goes low) that provides power to the
cooling fans. The cooling fans run from the time the AC Circuit Breaker is
powered ON until approximately ten minutes after the projector receives a power
Off command (AC Circuit Breaker still on).
When the projector receives a power ON command from the IR Remote, PC or
Laptop, the System Controller PCB receives a /LAMP_OK from the Arc Lamp
Power Supply. The System Controller PCB then drives the /LAMP_ENA signal
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Chapter 7---Troubleshooting
to the Arc Lamp Power Supply low. The Arc Lamp Power Supply delivers 170 V
to the Igniter, which generates a 32 kV pulse to the Arc Lamp and the Arc Lamp
lights. Once the Arc Lamp lights, the Arc Lamp Power Supply, the /LAMP_LIT
signal goes low and the voltage to the Igniter drops to between 25 V and 31 V.
The voltage from the Arc Lamp Power Supply stays at a steady output of 2 kW
during normal operation of the projector.
When the projector receives a power OFF command, the /LAMP_LIT and the
/LAMP_ENA signal both go high. This shuts off the Arc Lamp Power Supply.
The /FAN_ENA signal stays low for an additional ten minutes allowing the
cooling fans to cool down the Arc Lamp, the Light Pipe and the PCBs. After ten
minutes, the /FAN_ENA signal goes high, shutting off the cooling fans.
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Image Path
Figure 7-11 RGB Image path from VIC to CRT.
The image signals can be in the form of separate red, green and blue component
signals with separate horizontal and vertical sync signals or they can be a
composite image signal with all the image and sync signals combined into one
input signal. The image signals, if not already separate, are separated into red
green and blue color components, and horizontal and vertical syncs in the VIC.
The separated image and sync signals go to the Video Processor PCB. In the
Video Processor PCB the image signals are modified with Brightness, Contrast,
Gamma Correction, Sensitivity and Threshold. The modified image signals go to
the Video Amplifier PCB where they are go through an amplifier and on to the
CRTs.
The horizontal and vertical sync pulses are routed to the Raster Timing Generator
PCB. In the case of Sync-on- Green type sync pulses, the horizontal and vertical
syncs are stripped from the green image signal in the Video Processor PCB.
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Deflection Path
Figure 7-12 CRT Deflection path from Raster Timing Generator PCB.
The Raster Timing Generator PCB receives the horizontal and vertical sync
pulses from the Video Processor PCB, and uses a Phase Locked Loop circuit to
lock to the horizontal sync. It sends a sample of the horizontal frequency
(H_DRIVE) to the Horizontal Vertical Deflection PCB to set the timing of the
Horizontal Amplifier, a Switched Mode Power Supply that generates the
horizontal deflection sawtooth waveform. The Raster Timing Generator PCB
divides the range of horizontal scan frequencies into four groups or bands because
the retrace or flyback timing varies dramatically from the lowest frequency (15
kHz) to the highest frequency (90 kHz).
The Horizontal Vertical Deflection PCB generates the horizontal waveforms that
drive the CRT Yokes. Many of the geometric corrections are integrated into the
horizontal waveform at the Horizontal Vertical Deflection PCB such as
Pincushion, Keystone, Skew, and Bow. The vertical size is be adjusted on the
Horizontal Vertical Deflection PCB.
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Chapter 7---Troubleshooting
The Horizontal Vertical Deflection PCB outputs H_OUT_FLYBACK to the Scan
Reversal PCB. This is the horizontal deflection waveform that drives the
horizontal CRT deflection yokes. The H_RED+, GRN+, and BLU+ are the
horizontal deflection returns. The outputs of the vertical amplifier are V_RED+,
GRN+, and BLU+. The returns are V_RED-, GRN-, and BLU-.
The Convergence Deflection PCB receives a sample of the vertical frequency
from the Raster Timing Generator PCB (V_DRIVE) signal and generates a
sawtooth waveform ( V_RAMP). It sends this signal to the Vertical Amplifier on
the Horizontal Vertical Deflection PCB. It also sends geometric correction to
modulate the vertical deflection waveform (V_PARAB) to the Horizontal Vertical
Deflection PCB. The Convergence Deflection PCB sends convergence correction
data received from the System Controller PCB to the Scan Reversal PCB
(X_RED+, GRN+, and BLU+) and (Y_RED+, GRN+, and BLU+). The
convergence correction data goes from the Scan Reversal PCB to the
Convergence Yokes on each CRTs.
The Scan Reversal PCB sends the horizontal and vertical deflection waveforms to
the appropriate CRT. It also converts the waveform for floor/ceiling and front/rear
projector installations.
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Figure 7-13 CRT Deflection path between Horiz/Vert Deflection PCB,
Convergence Deflection PCB and Scan Reversal PCB.
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Figure 7-14 CRT Deflection path between the Scan Reversal PCB and CRT.
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CRT Protection
Figure 7-15 CRT Protection path
The CRT Protection circuit is designed to protect the CRTs in case any of the
CRTs is not receiving a horizontal or vertical deflection waveform. If there are no
deflection waveforms, the electron gun inside the CRT will shoot an electron
beam at the center of the CRT, burning a spot in the CRT phosphor that will be
visible on the screen. The CRT Protection circuit also protects the CRTs from
excessive beam current that may damage the CRT.
Deflection Waveform Detection
The CRT Protection circuit protects the CRTs by monitoring the deflection
waveforms in two different ways. On the Scan Reversal PCB, there is a H_SENS
and V_SENS signal for each CRT. These sense lines detect the presence of the
horizontal and vertical deflection waveforms. The horizontal and vertical sense
lines for each CRT combine into a RED, GRN, or BLU_DEFL_OK signal (see
Figure 7-16). These RED, GRN, or BLU_DEFL_OK signals combine into one
DEFL_OK signal that goes back to the Horizontal Vertical Deflection PCB. On
the Horizontal Vertical Deflection PCB, the DEFL_OK (normally high and the
/H-ENA (normally low) go into an NOR logic gate with an inverted input for the
H-ENA signal. The /H_ENA signal shuts down the horizontal amplifier during
changes in source input. If DEFL_OK goes low or /H_ENA goes high, the output
/SWEEP_OK goes high. If the /SWEEP_OK signal, on the Video Amplifier PCB,
goes high, the G1 supply and the G2 Regulator circuit shut down. On the Video
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Amplifier PCB the /SWEEP_OK becomes the /VA_OK signal and checks the
supply voltages such as +15 V, +6.2 V and +80 V. The /VA_OK LED
illuminates (see Video Amplifier PCB LED) if the supply voltages are present and
the /SWEEP_OK is low. The /VA_OK also goes to the High Voltage Power
Supply. On the High Voltage Power Supply, a logical “high” shuts down the high
voltage amplifier that generates the Anode, Focus, and G2 voltages. The /VA_OK
signal also goes to the Video Processor PCB where a logical “high” shuts down
the G2 control voltages.
Yoke Connector Detection
The CRT Protection circuit also ensures that CRT Yoke connectors are properly
installed. It does this with the H_LOCK+/- circuit. This series circuit goes from
the Horizontal Vertical Deflection PCB to the Scan Reversal PCB, through each
CRT Yoke connector, and back to the Horizontal Vertical Deflection PCB. The
H_LOCK+ has +15 V applied to it on the Horizontal Vertical Deflection PCB. If
all the CRT Yoke connectors are properly installed H-LOCK+ and H_LOCKwill both measure +5 V. If the any one of the connectors is not properly installed,
H_LOCK+ will measure +15 V and H_LOCK- will measure 0 V. If H_LOCK- is
at 0 V. This shuts down the horizontal amplifier circuit that generates the
horizontal deflection waveform.
CRT Beam Current
Another function the CRT Protection circuit performs is to monitor the beam
current of each CRT. The Video Amplifier PCB outputs a current sense line
(RED, GRN, and BLU BEAM) from each image amplifier circuits. The Video
Processor PCB receives these current sense lines and compares them to a
reference. If the beam current of any CRT exceeds 250 µA, the Beam current
LED illuminates orange, and the Video Processor PCB reduces Contrast. If
reducing Contrast does not bring the CRT beam current below 250 µA, the Video
Processor PCB reduces the G2 voltage until the beam current drops below the
limit.
7-20
Model 250 Service Manual
Chapter 7---Troubleshooting
Figure 7-16 CRT Protection path between the Scan Reversal PCB and CRT.
Model 250 Service Manual
7-21
Chapter 7---Troubleshooting
7.4 Error Codes
For certain errors that may occur in the Model 250 Projector the software
provides error codes that are helpful in determining the nature of the problem.
These error codes can be seen on the left side of the monitor screen when using a
PC connected to Port A or Port B.
Table 7-1 Error Categories:
Category
Number
Error Category
Description
1
CEXEC
Operating System.
2
FLASH HW
Flash Memory HW driver.
3
IIC HANDLER
IIC Handler for Convergence/Deflection PCB,
Horizontal/Vertical Deflection PCB, Raster
Timing Generator PCB, Video Amplifier PCB,
Video Processor PCB.
4
POWER ON/OFF
Power On Sequencing.
5
FLASH MANAGER
Flash Memory Data Manager.
6
VIDEO SWITCHER
EXTRON or JVC Video Switcher Handler.
7
ANSI OUTPUT
ANSI Output Display process.
8
UI CHAN/SRC
User Interface VIC Configuration Handler for
Channel/SRC Data.
9
VIDEO INPUT CARD
VIC Card Handler.
10
HARDWARE
Misc HW (shutters, etc.).
The error codes listed in Table 7-2 describe problems associated with software
(Version 2.6.0) and hardware while the projector is operating. The first column of
the table lists the error number code that appears on the PC screen. The second
column describes the on-screen text. The third column provides a description of
the problem and any other pertinent information.
Table 7-2 Error Codes.
Error
Number
7-22
On-Screen Text
Description
1.5
“Invalid read/wrt”
Software error-mismatch. Open mode vs. Write
or Read command.
1.12
“Ser parity error”
Serial Port Parity error-not currently used.
1.13
“Bad dev I/O oper”
Software error-invalid I/O request.
1.27
“Timeout on Read”
Software error-unexpected timeout on Read.
Model 250 Service Manual
Chapter 7---Troubleshooting
1.34
“No mem available”
Software error-no heap available for memory
allocation.
2.1
“Invalid Sector”
Software error-invalid Flash sector number.
2.2
“Write Timeout”
Flash Memory Write Failure.
2.3
“Erase Timeout”
Flash Memory Erase Sector Failure.
2.4
“Verify Error”
Flash Memory Write Verify Failure.
NOTE: Category 3 error codes may occur when power is interrupted by opening the
cover interlock switches or during power brown-outs.
3.1
“Pin Timeout”
IIC Slave HW protocol error-possible on each
byte transfer.
3.2
“BB Timeout”
IIC Slave HW protocol error-1st error possible
on Read or Write.
3.3
“No Slave Ack”
IIC Slave HW protocol error-missing
acknowledgement on byte transfer. NOTE: This
error occurs if the slave is missing. During
Power On, this error is reported in the POWER
category.
4.1
“CD PCA Missing”
“No Slave Ack” on first poll of Convergence/
Deflection PCB.
4.2
“CD PCA Not OK”
/CD_OK is high (BAD).
4.3
“”HVD PCA Missing”
“No Slave Ack” status on first poll of
Horizontal/Vertical Deflection PCB.
4.4
“HVD PCA Not OK”
HVD_OK is High (BAD)-[/HVD_OK requires
RTG Timing.
4.5
“VA PCA Missing”
“No Slave Ack” status on first poll of Video
Processor.
4.6
“VA PCA Not OK”
/VA_OK is High (BAD).
4.7
“VP PCA Missing”
“No Slave Ack” status on first poll of VP.
4.8
“VP PCA Not OK”
VP_OK is High (BAD)
4.9
“RTG PCA Missing”
“No Slave Ack” status on first poll of RTG
4.10
“RTG PCA Not OK”
RTG_OK is High (BAD)
4.14
“Lamp Startup”
Lamp Failed to light (/LAMP_LIT_B not Low
for 3 seconds out of 20 seconds.)
4.15
“Low Voltage PS”
Low Voltage PS failed (/LV_OK_B is High).
4.16
“High Voltage PS”
High Voltage PS failed (/HV_OK_B is High).
Model 250 Service Manual
7-23
Chapter 7---Troubleshooting
4.17
“VIC1 Board Not OK”
/VIC_OK is High (BAD) on VIC Slot 1.
4.18
“VIC 2 Board Not Ok”
/VIC_OK is High (BAD) on VIC Slot 2
4.19
“VIC3 Board Not OK”
/VIC_OK is High (BAD) on VIC Slot 3
4.20
“VIC1 Invalid Type”
Software does not support VIC_ID in Slot 1
4.21
“VIC2 Invalid Type”
Software does not support VIC_ID in Slot 2
4.22
“VIC3 Invalid Type”
Software does not support VIC_ID in Slot 3
4.23
4.24
“Shutters Missing”
"Lamp Start Not On"
One or more shutters not installed (BAD)
/LAMP_OK is high, lamp module not installed,
jumper missing, ALPS bad.
No error codes in Category 5 (Flash Manager)
Most Category 6 error codes indicate RS232 communication errors and apply to
Switchers only.
6.1
“Sync Timeout”
No Header found in data stream - possible baud
rate error.
6.2
“No Char Repeat”
Expected data characters to be repeated - failed.
6.3
“Invalid Format”
Data not in Extron or JVC Switcher format.
7.1
“Write Len Error”
Ansi Output to RS232 port was interrupted incomplete.
8.1
“VIC Slot is empty”
User has selected a Channel - VIC is not present.
8.2
“VIC Type Changed”
User has selected a Channel - VIC type has
changed. User may have swapped a VIC into an
incorrect slot.
8.3
“Interpol Blocked”
Software process error - Interpolation Process
not allowed to run by higher priority processes.
9.1
“Quad Dec Not Init”
HW: Quad Decoder failed Startup Sequence.
10.1
“Shutter Stat BAD”
One or more shutters reading wrong status.
One other error may appear on the monitor screen with the statement “Assertion
Failed” (only if the PC is connected to Port A). This is a very rare but serious
error. If it occurs:
1. Copy the three lines that appear on the screen.
2. Note what occurred just prior to this failure.
3. Call Hughes-JVC at 1 800 392-9666.
7-24
Model 250 Service Manual
Chapter 7---Troubleshooting
7.5 Troubleshooting Guide
Table 7-3 lists some common projector problems, what to check when problems
occur, and offers possible solutions. It indicates the section in this Service Manual
that provides some related information on the problem. If the User’s Guide
contains pertinent information, the appropriate section will be given.
Table 7-3 Troubleshooting Guide
Problem
No Power
No Picture
Arc Lamp
Check
Main Circuit Breaker on
Projector rear panel.
Main Circuit Breaker
fails when reset.
Possible Solution
Reset Circuit Breaker.
Section 3.2
Verify input power is
Section 3.2
correct. Replace defective
Low Voltage Power
Supply or Arc Lamp
Power Supply.
Reposition projector
Section 6.1
cover.
Projector cover not
enabling interlock
switch?
Correct channel input & Select correct channel
VIC selected?
and VIC.
Arc Lamp turned off.
Restart projector.
System power turned off. Restart projector.
Signal source
Verify signal source is
turned on and properly
connected.
HIDE command
Unhide image with the
invoked?
HIDE key on the remote.
One color is missing.
Turn on the missing color
with the HIDE key.
No image or raster on
Replace defective CRT or
one CRT.
Video Amplifier Board.
Arc Lamp will not light. Replace worn out Arc
Clicking noise is heard
Lamp.
when projector is turned
on.
Clicking noise not
LVPS, ALPS, or Ignitor
audible when projector is faulty. Replace LVPS,
turned on.
ALPS, or Ignitor.
Arc Lamp ignites but will Replace defective Ignitor.
not stay lit.
Model 250 Service Manual
Section
User’s Guide
section 4.6
User’s Guide 4.3.
User’s Guide 4.3.
User’s Guide 3.5.
Section 6.9, 6.10
Section 4.1
Section 3.3, 3.4
Section 3.4
7-25
Chapter 7---Troubleshooting
Troubleshooting on the Backplane PCB
The connectors on the Backplane PCB provide one of the more accessible places
to probe voltages and signals that may be useful for troubleshooting purposes (see
Figure 7-18 and associated list of signals and voltages).
Figure 7-17 Backplane Diagram (left side)
7-26
Model 250 Service Manual
Chapter 7---Troubleshooting
Figure 7-18 Backplane Diagram (middle section)
The following is a list of pins that would be helpful for troubleshooting purposes.
Low Voltage Power Supply (J8)
High Voltage Power Supply (J7)
Pin #
8
9
10
11
12
13
14
15
16
17
18
1-7
Pin #
5
8
9
10
11
12
1-4
Signal or Voltage
/LV_ENA
/LV_OK
+24 V_FANS
_5.1 V Stdby
+5.1 V
+6.2 V
+15 V
-15 V
+80 V
/COVER_ON
/FAN_ENA
GND
Signal or Voltage
/HV_OK
+80 V
+15 V
-15 V
G1 SUPPLY
/VA_OK
GND
Arc Lamp Power Supply (9)
Pin #
2
3
4
5
1, 6
Signal or Voltage
/LAMP_LIT
/LAMP_OK
/LAMP_ENA
/COVER_ON
GND
Model 250 Service Manual
7-27
Chapter 7---Troubleshooting
Figure 7-19 Backplane Diagram (right side)
7-28
Model 250 Service Manual
Chapter 7---Troubleshooting
Model 250 Service Manual
7-29
Chapter 8---Software and Protocol
8.0 Software and Protocol
Contents
8.1 Software Updating........................................................................................ 8-1
8.2 Importing/Exporting..................................................................................... 8-5
Configuration ............................................................................................. 8-5
Exporting.................................................................................................... 8-6
Importing.................................................................................................... 8-7
Null Modem Adapter ................................................................................. 8-9
8.3 Terminals and Communication Protocol...................................................... 8-10
Terminals.................................................................................................... 8-10
Terminal Preferences.................................................................................. 8-10
Communications Protocol .......................................................................... 8-11
8.1
Software Updating
The Model 250 software resides in Flash Memory and is updated via the
projector's serial Port A. To perform an update, a disk containing the updated
Boot Software (boot.hex) and/or System Software (zsys.hex) and a PC with
Windows 3.1 (Windows 95/98 with Procomm Plus fax/modem software) is
required to perform update.
Boot Manager Software and System Software are separate products. Each may be
updated independently. The System Software will depend on a specific version of
the Boot Manager. Refer to the System Software release bulletin for Boot
Manager version dependencies.
To perform software upgrade:
1. Verify that the projector circuit breaker is off. Use a Null Modem cable to
connect a PC to the projector’s Serial Port A (Terminal-In).
2. Start Windows 3.1.
3. Click on the terminal icon from the Accessories Directory.
4. From the Terminal menu, select Settings-Terminal Emulation and click on
DEC-VT-100 (ANSI).
Select OK.
5. Under Settings, choose Terminal Preferences.
!
!
!
Under Terminal Preferences the following selections are appropriate;
Terminal Modes=Sound
CR->CR/LF=Both off
Columns=80
Model 250 Service Manual
8-1
Chapter 8---Software and Protocol
Cursor=Block & Blink
! Terminal Font=Fixedsys 15
! Translation=None,
! Show Scroll Bars=On
! Buffer Lines=100
! Use Function Arrow
! Control Keys for Windows=Off
Select OK.
!
6. Under Settings select Text Transfer=Standard Flow Control. Select OK.
7. Under Settings select Communications and choose;
Connector=select the PC port being used
! Baud Rate=9600 or 19200 (depending on the System Controller
Switch block Pos 4-see note below this step)
! Data Bits=8, Stop Bits=1, Parity=None
! Parity Check=Off, Carrier Detect=Off, Flow Control=XON/XOFF
Select OK.
NOTE: Switch position 4 on the switch block at the card edge of the
System Controller (see Figure 7-2) controls the baud rate for Serial Port A
for the Boot Manager and System Software. Down=9600, Up=19200.
Ensure the other SCB switches (1, 2, and 3) are in the Down position.
!
8. Turn the projector circuit breaker on while depressing and holding down
the service mode switch on the System Controller PCB (see Figure 7-1).
Verify that "Boot Manager" appears on the terminal monitor. The Power
On LED stays Red.
Alternate for Step 9: In "Power Off" Standby mode, Press "Control, Shift
+ _ (underscore), hex "IF (international keyboard may vary in key
placement).
9. The following should be displayed on the Windows Terminal screen
(where x.x.0 is the currently loaded Boot Manager version (e.g. 0.9.0 or
1.1.0).
–Boot Manager Ver x.x.0 (Service Mode Startup)
–Copyright (c) 1994 Hughes JVC Technology
–Command: _
10. Verify that the Boot Manager version is correct. If it is necessary to update
the Boot Manager, perform the following steps. If the Boot Manager is
already up to date, skip to Step 12A to update the System Software.
11A. Enter the command "loadboot" at the prompt. You should see the
following output:
Command: loadboot
Boot Manager software update procedure
8-2
Model 250 Service Manual
Chapter 8---Software and Protocol
***WARNING: IMPROPER USE MAY MAKE THIS SYSTEM
UNBOOTABLE*** (This warning relates to the
Flash Memory
updating that occurs in Step
11D. Do not turn projector power off while the
Flash Memory is updating)
Memory buffer reset to 0xff
Begin your S-Record upload now (Esc to abort).
11B. From the Windows Terminal Menu (normally in Accessories window),
select "Transfers/Send Text File", then select "List Files of Type: All
Files", and select the disk and/or directory with the Model 250 software.
You should see a file named "boot.hex". Select this file and press the OK
button to begin the upload. Uploading takes about 20 minutes (9600 bps).
11C. During upload, a progress indicator updates the number of records
received. At the completion of the upload, the system will display the
following (numerical values are for example only and depend on the
Boot Manager version):
S-Records processed: 823
Upload Successful
Address Range: 0x00000000-0x00006687
Bytes Loaded:
26248
***WARNING: FLASH WILL NOW BE UPDATED***
Press Enter to continue, Esc to abort.
11D. The system has verified that the load module is correct and is ready to
update the Flash. Press Enter to perform the update (press Esc now to
abort the update with no changes). While the Flash memory is being
updated (15-30 seconds), DO NOT turn off the projector circuit breaker
or the machine could be made unbootable, requiring a new set of flash
chips to be installed. When the update is complete, the system will
display the following:
Reprogramming Flash Sector 0 1
Boot Manager software update successful
Command: _
The Boot software has been successfully updated. To restart the projector
under control of the updated boot manager, enter the "reboot" command
while depressing the service mode switch (see Figure 7-1). The projector
will now restart with the updated boot manager software.
NOTE: If normal software starts, see Step 9 to reenter Boot Manager.)
You should see the following displayed, where y.y.0 is the updated Boot
Manager's version.
Model 250 Service Manual
8-3
Chapter 8---Software and Protocol
Boot Manager Ver y.y.0 (Service Mode Startup)
Copyright (c) 1994-1996 Hughes-JVC
Technology
Command: _
12A. To update the System Software from the Boot Manager prompt:
12B. Type in the command “loadsys” at the prompt. The following should be
displayed:
Command: loadsys
System software update procedure
***WARNING: IMPROPER USE MAY MAKE THIS
SYSTEM
UNBOOTABLE*** (NOTE: This warning
relates to the Flash Memory updating that occurs
in Step 12D below. Do not turn projector power
off while the Flash Memory is
updating.)
Memory buffer reset to Oxff
Begin your S-Record upload now (Esc to abort)
12C. Select “Transfers/Send Text File” from the Windows Terminal Menu
(normally in Accessories window). In the “Send Text File Dialog” box,
select “List Files of Type: All Files” and select the disk and/or directory
with the Model 250 software. Select file named “zsys.hex”. Press OK to
start upload. Uploading takes about 20 minutes (9600 bps)
12D. During upload, a progress indicator updates the number of records
received. When the upload is complete, the system will display the
following (numerical values are for example only and depend on the
System Software version):
S-Records processed:11282
Upload Successful
Address Range: 0x00020000-0x000781cf
Bytes Loaded:360912
***WARNING: FLASH WILL NOW BE UPDATED***
Press Enter to continue, Esc to abort
12E. At this point the system has verified that the load module is correct and
is ready to update the Flash memory. Press Enter to perform the update
(Esc will abort the update process with no changes). While the Flash is
being updated (approx. 15-30 seconds), DO NOT turn off the projector
circuit breaker, this may make the machine unbootable, requiring a new
set of flash chips to be installed. When the update is complete, the system
will display the following:
Reprogramming Flash Sector 2 3 4 5 6 7 8 9
System software update successful
Command: _
8-4
Model 250 Service Manual
Chapter 8---Software and Protocol
The software update is complete. To restart the projector, type in the “sys” or
“reboot” command and press Enter. The projector will now restart with the
updated System Software.
8.2
Importing/Exporting
Configuration
Data Export / Import Procedure - Rev 1.0.0
This appendix defines the steps to perform a Configuration Data Export & Import
from the Model 250 projector to a Host Computer. The Host Computer can be any
system that has RS232 download and upload capability, including an IBM-PC
compatible, an Apple MacIntosh, or a UNIX system. This paper describes the
procedures for an IBM-PC running the Windows 3.1 OS. We will use the
Windows “TERMINAL” application for communication with the projector. Other
Terminal emulation programs can be used (ProComm with Windows 95/98), but
all testing has been done with the TERMINAL application.
Note 1: The TERMINAL application setup is the same as for controlling the
projector via an ANSI TERMINAL (see section 8-3 Terminals and Protocol).
Note 2: Export/Import can be performed on either Port A or Port B. The Port
must be configured for ANSI Terminal. Port A speed is determined by DIP
SWITCH #4 on the System Controller board. UP is 9600 baud, DOWN is 19200
Baud. Port B can be configured for 2400, 9600 (default), or 19200 through the
Comm Setup Menu. If both Port A and Port B are ANSI Terminals, PORT A
must be used for Export/Import, so to use Port B, set Port A Device = None or
Switcher, Port B Device = ANSI.
Remember to Power Off (Control+P) and HW RESET (Push RESET button figure 5-1 in Service Manual- or Circuit Breaker-on rear panel) after changing any
configuration parameters.
CAUTION!
If you use 19200 Baud, your computer must
have a 16550 UART installed on the Comm Port. An unbuffered 8550
UART will lose data during EXPORT. This data loss cannot be detected
until a later IMPORT is attempted. Use 9600 if you are not sure. In all
cases use SOFTWARE FLOW CONTROL (XON/XOFF).
CAUTION! Laptop computer users must disable Advance
Power Management (APM) during an Export. APM power pulling causes
loss of data.
Model 250 Service Manual
8-5
Chapter 8---Software and Protocol
Exporting
1. Make sure the Windows TERMINAL program is configured for
SOFTWARE FLOW CONTROL (XON/XOFF). A corrupt Export file
will result if SW flow control is not used.
2. Choose the directory and filename for saving the Export Data. The
Windows TERMINAL: Transfers: Receive Text File... dialog box will
default to the c:\windows directory and no file. Create a directory (like
\TEMP) (or have an existing one in mind) before starting the export
process.
3. Model 250 Menu: 7. System + 5. Maintenance + 5. Export
=================================
|
Export Configuration
|
| Start RECEIVE TEXT Download
|
| to Host on Serial PORT A
|
|
|
<ENTER> to Continue
|
|
< ESC> to Cancel
|
|
=================================
4. Windows TERMINAL: Transfers + Receive Text File....
5. Directories - set directory to desired download directory (C:\TEMP)
6. File Name: - Type desired File Name (for example: export1.txt)
7. Select OK with mouse or press Enter key (dialog will be removed)
8. Verify TERMINAL screen shows status line at bottom:
Stop, Pause, Bytes: 0, Receiving: EXPORT1.TXT
9. Model 250 Menu:
Press ENTER key to start export download. NOTE: Some VT100
Emulator programs (ProComm) will send the ENTER automatically when
step 4.3 above is performed. Expect 10 minutes to export 20 sources
(500,000 bytes) at 9600 baud).
Data Transfer will begin and continue until all source, channel, channelsource combination, and system data has been exported. The following
dialog is displayed on the projector screen during the transfer.
=================================
|
Export Configuration
|
| EXPORT IN PROGRESS ... wait |
| - Press ESC to Abort
|
=================================
The following message is sent at the end of the export data.
##########################
# Export Complete
#
# STOP Host Download Now #
# Then, Press ESC
#
##########################
8-6
Model 250 Service Manual
Chapter 8---Software and Protocol
. END
A similar message is displayed on the projector screen :
=================================
|
Export Configuration
|
| EXPORT COMPLETE
|
| -> STOP Host Download
|
| -> THEN Press ESC
|
=================================
10. Windows TERMINAL:
Select the Windows TERMINAL STOP button with the mouse to end the
Receive Text File... transfer.
11. Model 250 Menu:
Press Esc to exit the projector Export operation and return to the
Maintenance Menu.
Importing
1. Know the directory and filename for uploading the Import Data. The
Windows TERMINAL: Transfers: Send Text File... dialog box will
default to the C:\windows directory which contains several *.txt files SETUP.TXT is NOT a Projector EXPORT file!
2. Import will alter all projector setup data. Prior to starting, several
warnings are displayed to prevent unintentional loss of setup data.
3. Model 250 Menu: 7. System + 5. Maintenance + 6. Import
=================================
WARNING
|
| Importing New Configuration |
| ALL SETUP DATA WILL BE
| CHANGED!
|
|
<ENTER> to Continue
|
|
< ESC> to Cancel
|
|
=================================
|
4. Press ENTER to continue with the Import.
=================================
|
Import Configuration
|
| Old Configuration will be
|
| restored if import is Aborted |
|
|
<ENTER> to Continue
|
|
< ESC> to Cancel
|
|
=================================
5. Press ENTER to continue with the Import.
=================================
Model 250 Service Manual
8-7
Chapter 8---Software and Protocol
|
Import Configuration
|
| Start SEND TEXT Upload from
|
| Host on Serial PORT A
|
| -To Abort:
|
| ->Stop Host Upload,
|
| ->THEN Press ESC to Abort
|
=================================
6. Windows TERMINAL: Transfers + Send Text File....
6.1 Directories - set directory to desired upload directory (C:\TEMP)
6.2 File Name: - Type desired File Name (for example: import1.txt)
6.3 Select OK with mouse or press Enter key (upload begins)
6.4 Verify TERMINAL screen shows status line at bottom:
Stop, Pause, “% complete bar”, Sending: EXPORT1.TXT
6.5 Data transfer will continue until complete or an error occurs or the
User Aborts: Expect 10 minutes to import 20 sources (500,000 bytes)
at 9600 baud.
6.6 At successful end, TERMINAL will remove the bottom line.
7. Model 250 Menu:
When the projector detects the successful end of the transfer the following
screen is displayed:
=================================
|
Import Configuration
|
| IMPORT COMPLETE
|
| New Configuration is active |
|
|
| - Press ESC to Continue
|
=================================
Press ESC to exit the projector Import operation and return to the
Maintenance Menu. There is a 10 second pause before the screen is
redrawn.
8. USER ABORT:
Windows TERMINAL: FIRST press STOP to end the Host Upload
transfer.
Model 250 Menu: THEN press ESC to abort the projector Import
operation.
=================================
Import Failed
|
|
| IMPORT ABORTED BY USER
|
|
Old Data was Restored.
|
| - STOP Host SEND DATA,
|
|
THEN Press ESC
|
=================================
8-8
Model 250 Service Manual
Chapter 8---Software and Protocol
FINALLY, press ESC to exit the projector Import operation and return to
the Maintenance Menu. There is a 10 second pause before the screen is redrawn.
9. DATA TRANSFER ERROR (Example)
Model 250 Menu will display:
=================================
Import Failed
|
|
| Bad EXPORT File Format
|
|
Old Data was Restored.
|
| -> STOP Host SEND DATA,
|
| -> THEN Press ESC
|
=================================
9.1 Windows TERMINAL: FIRST press STOP to end the Host Upload
transfer.
9.2 Model 250 Menu: THEN press ESC to exit the projector Import
operation and return
to the Maintenance Menu. There is a 10second pause before the screen is redrawn.
Null Modem Adapter
A Null Modem Adapter is needed to import data to or export data from the Model
250 Projector. The Null Modem Adapter allows the projector to communicate to a
PC or Laptop computer through a serial cable. In essence, it tricks the projector
into thinking it is a modem.
For the pinout of Terminal-In (Port A) and Control-Out (Port B) refer to Figure
8-1
Figure 8-1 Terminal-In and Control-Out pinout.
Model 250 Service Manual
8-9
Chapter 8---Software and Protocol
8.3
Terminals and Communication Protocols
Terminals
The projector can be controlled by a VT-100 terminal. If a VT-100 is not
available, a PC with Windows 3.1 or ProComm for DOS can emulate a VT-100.
Table 8-1 shows the equivalent commands for the terminal and both remotes.
1. From Windows Program Manager, select TERMINAL then SETTINGS.
2. Select TERMINAL EMULATION from SETTINGS menu.
3. Select DEC VT-100 (ANSI) (may already be selected).
4. Use a Null Modem cable to connect between the projector and the
terminal.
5. Use the TERMINAL PREFERENCES and COMMUNICATIONS
PROTOCOL below for Windows setup.
Terminal Preferences
Select SETTINGS again from the menu bar. Select TERMINAL
PREFERENCES. Set the following modes:
Table 8-1 Terminal preference settings
Line Wrap
Yes
CR"CR/LF:
Local Echo
No
Inbound
No
Sound
Yes
Outbound
No
Columns:
Cursor:
80:
Yes
Block:
Yes
132:
No
Underline:
No
Blink:
Yes
Terminal Font:
Courier 12
Translations
NONE
IBM to ANSI
No
Buffer Lines
100
Terminal Show:
Scroll Bars
Use Function Arrow
and Control keys for
Windows
8-10
Yes
No
Model 250 Service Manual
Chapter 8---Software and Protocol
Communications Protocol
Select SETTINGS using the menu bar, then select COMMUNICATIONS. Set the
following communications parameters and modes.
Table 8-2 Communications settings
Baud Rate
9600
Stop Bits
1
Data Bits
8
Flow Control
Xon/Xoff
Parity
None
Carrier Detect
No
Parity Check
No
Connector
Com1-This is PC
configuration
dependent.
Select FILE from the menu bar and select NEW. Under File Name enter VT100.TRM. This will allow the user to select the file VT-100.TRM with the
above parameters saved for future use.
Table 8-3 VT-100 Terminal and Remote Command Equivalents
Keyboard
Executive
Service
Action
Input
Remote Keys
Remote Keys
Power OFF
CTRL + F
(All)
Power ON (All)
CTRL + U
Power ON/OFF
CTRL-P
POWER
POWER
Power
CTRL + E
ON/OFFElectronics only
Power ON/OFF
CTRL + L
Lamp
Left Arrow
Left Arrow
Left Arrow
Left Arrow
Dec.
Hex.
6
6
21
16
5
15
10
5
12
0C
1B 5B
44*
1B 5B
43*
1B 5B
41*
1B 5B
42*
1B
42
55
49
Right Arrow
Right Arrow
Right Arrow
Up Arrow
Up Arrow
Up Arrow
Down Arrow
Down Arrow
Down Arrow
Down Arrow
Back out of
menu
Blanking
Bow, H & V
Brightness
Esc
ESC
ESC
27 91
68*
27 91
67*
27 91
65*
27 91
66*
27
BRT
BLANK
BOW
BRT
66
85
73
Right Arrow
Up Arrow
Model 250 Service Manual
B
U
I
8-11
Chapter 8---Software and Protocol
Center, H & V
(RGB)
Change channel
Color
Contrast (RGB)
Edge, H & V
(RGB)
Enter
Escape
Hide
Keystone, H &
V
Lens adjust
Linearity, H
&V (RGB)
Menu
Mode
Numeric
Onscreen
Phase
Picture
sharpness
Picture tint
Pincushion, H
&V
RGB toggle
Size, H & V
Test pattern
display
Skew, H & V
(RGB)
Threshold
Sensitivity
Registration
Redraw
Terminal
Screen
Reboot**
Restart System
Software***
8-12
P
POS
80
50
Number +
Enter
Y
C
E
Channel # +
Enter
COLOR
CONT
Channel # +
Enter
COLOR
CONT
EDGE
48-57
89
67
69
30-39 +
0D
59
43
45
Enter
Esc
F
K
ENTER
ESC
HIDE
ENTER
ESC
HIDE
KEY
13
27
70
75
0D
1B
46
4B
LENS + Arrows
LIN
65
76
41
4C
MENU
MODE
0-9
ONSCRN
PHASE
SHARP
32
77
48-57
79
72
88
20
4D
30-39
4F
48
58
A
L
Spacebar
M
0-9
O
H
X
MENU
MODE
0-9
ONSCRN
Z
N
TINT
TINT
PIN
90
78
5A
4E
R
S
T
RGB
RGB
SIZE
PATTERN
82
83
84
52
53
54
W
SKEW
87
57
D
V
G
|
THRESH
SENS
XYREG
68
86
71
124
44
56
47
7C
31
1F
30
1E
CTRL+Shift+
_
CTRL+Shift+
^
SHARP
Model 250 Service Manual
Chapter 8---Software and Protocol
*The Arrow keys are a sequence of Decimal or Hex numbers representing the
sequence of Escape, Left Bracket, and A, B, C, or D depending on which arrow Is
pressed. The first number represents the Escape key, the second number
represents the Left Bracket, and the third number represents the letter
corresponding to the Arrow Key pressed.
**Refer to Section 8.1, Software Updating.
***Must be done for a software change or port configuration change (device,
speed) to take effect.
Model 250 Service Manual
8-13
Chapter 8---Software and Protocol
8-14
Model 250 Service Manual
Chapter 9---Parts List
9.0 Parts List
Contents
9.1 Replacement Parts List................................................................................. 9-1
9.2 Spares ........................................................................................................... 9-3
9.1
Replacement Parts List
Table 9-1 Replacement parts list
Description
Arc Lamp Module
Cathode Ray Tube (CRT)
Contrast Enhancer
CRT/Yoke Assembly
Ignitor Assembly, (Ignitor & Laser P.S.)
ILA®, SM Moving 3 x 4 Video (High Contrast)
Add for Blue -14, for Green -15, for Red -16.
Lens, Relay
Manual, Operation (User’s Guide)
Manual, Service
PCA Convergence Deflection
PCA Horizontal/Vertical Deflection
PCA Raster Timing Generator
PCA System Controller
PCA Video Amplifier
PCA Video Processor
PCA, Backplane
PCA, Graphics Enhancer Plus RGBHV VIC
PCA, RGBHV VIC
PCA, YPbPr VIC (Option)
PCA, 4-Input (Quad) RGBHV VIC (Option)
PCA, Quad Standard Decoder VIC (Option)
PCA, Quad Standard Decoder/Line Doubler VIC
(Optional
PCA, Scan Reversal
Model 250 Service Manual
Part no.
106298
105199
104247
105384
106570
102630
106533
106785
106784
105210
106838
105238
104678
105232
105234
102595
106183
102597
106340
103668
103545
105376
102585
9-1
Chapter 9---Parts List
Description
Power Cord, USA/Japan
Power Cord, Europe
Power Supply, Arc Lamp
Power Supply, High Voltage
Power Supply, Low Voltage
Prism Tank Assembly
Projection Lens, 0.96:1, Fixed
Projection Lens, 1.5:1, Fixed
Projection Lens, 2.4:1, Fixed (Simulator)
Projection Lens, 5.6:1, Fixed
Projection Lens, Zoom (2:1 - 4:1)
Remote Control, Executive
Remote Control, Service
Remote Control, Tethered Technician
Yoke Assembly, CRT
9-2
Part no.
104499
103939
105216
102566
102520
103942
105134
106687
103592
104337
103746
105576
105575
105245
103467
Model 250 Service Manual
Chapter 9---Parts List
9.2
Spares
It may be advisable to maintain a supply of spares for the projector to minimize
downtime. This is particularly important when projectors are being operated on a
continuous basis or when multiple projectors are needed. Table 9-2, below,
provides a list of the spares that HJT recommends for one to four projectors.
Table 9-2 Recommended minimum spares
Part no.
Description
Quantity
105236
PCA Horiz/Vert Deflection
1
105210
PCA Conv/Defl
1
105232
PCA Video Amplifier
1
105234
PCA Video Processor
1
104678
PCA System Controller
1
105238
PCA Raster Timing Gen.
1
102585
PCA Scan Reversal
1
102597
PCA Graphics Enhancer Plus
VIC
1
102520
Low Voltage Power Supply
1
105216
Arc Lamp Power Supply
1
102566
High Voltage Power Supply
1
106298
Arc Lamp Module
Model 250 Service Manual
1-4
9-3
Chapter 9---Parts List
9-4
Model 250 Service Manual
Glossary
Glossary of Terms
Amorphous
Without definite form; not crystallized.
Arc Lamp
The high intensity light source in the Model 250
projector. The Xenon Arc Lamp operates at high
temperatures (160° to 200°) and produces
dangerously intensive light with hazardous levels
of ultraviolet and infrared radiation.
Aspect Ratio
The ratio of the picture width to picture height.
The standard U.S. television aspect ratio is four
units wide to three units high (4:3).
Bandwidth
Bandwidth is the difference between the lowest
and highest frequencies transmitted or received. In
digital formats it is measured in bits per second
and in communications, it is measured in Hertz.
Wider bandwidth provides more information or
picture detail capability.
Chrominance
Abbreviated as “C”. The portion of the YPbPr
and S-image signal that contains the color
information signal.
Cold Mirror
Mirror that absorbs infrared light so that its
reflection contains only “cold light” or light that
does not transmit appreciable heat. Because of
this absorption of infrared heat radiation, “cold
mirrors” get quite hot.
Cross-member Assembly
Assembly attached to the main chassis that
crosses over the top of the midsection of the
projector. Used to mount the front and rear
covers.
CRT (Cathode Ray Tube)
The Cathode Ray Tube is used as a display screen
in televisions and computer monitors. Commonly
referred to as the picture tube. The Model 250
projector uses three CRTs.
Dichroic Mirrors
The white light of the xenon arc lamp is separated
into red, green and blue by means of dichroic
beamsplitters that reflect only one color and pass
all others.
Model 250 Service Manual
A-1
Glossary
A-2
Field
One half of a complete video frame. Odd lines in
one field and even lines in another make up one
frame.
Frame
One complete TV picture or screen of
information. It is composed of two fields and has
a total of 525 scanning lines in NTSC
transmission.
Horizontal Scan
Reversal Jumper
Reverses the image projection for front or rear
projection. Located on the Horizontal Deflection
Board and Scan Reversal PCB.
Horizontal Size Coils
Adjustment coils on the Scan Reversal Board.
Used to adjust the horizontal size (width).
Hot Spot
The Arc Lamp’s brightest area on the screen.
Used to align and focus the Arc Lamp.
Hue
Also referred to as tint. A specific color such a
blue, pink or aqua. Hue or tint control on a
display device adjusts red/green balance.
Ignitor
Provides a momentary high voltage to excite the
gases in the Xenon Arc Lamp to ignite.
Image Light Amplifier
ILA®
A device that uses low-intensity images to phase
modulate a high-intensity light through a liquid
crystal layer. It is a key component in
producing very bright, high resolution images
from Hughes-JVC large-screen projectors.
Image Mirror
Also referred to as a “Steering Mirror”. It directs
the blue and red images toward the Combining
Prism.
Interlacing
The technique that refreshes a display screen by
alternately displaying all the odd lines (field one)
and then all the even lines (field two) of one
frame.
I/R Detector
The Model 250 Projector has two I/R Detectors,
one in front, one in back. These windows receive
projector control signals from the I/R Remote
Control.
Laser Power Supply
Provides boost voltage through a spark gap to the
Ignitor.
Model 250 Service Manual
Glossary
Lumen
A unit of measure of the flow, or rate of emission,
of light measured with a Light Meter. An
ordinary wax candle generates 13 lumens while a
100-watt bulb generates 1,200 lumens.
Luminance
Abbreviated as "Y." The portion of the YPbPr
and S-image signal that contains the black and
white information, which affects brightness.
Noise
An undesirable electrical interference of a signal.
Overscanning
Displaying less than the complete area of an
image to a viewer (i.e., scanning beyond the
visible area). All TV sets are overscanned at least
slightly, so that viewers do not see blanking.
Raster
The area illuminated by the scan lines on a CRT.
Resolution
The degree of sharpness of a displayed or printed
character or image. The amount of detail in a
picture. On a display screen, resolution is
expressed as the number of horizontal dots
(columns) by the number of vertical lines (rows).
For example, a 680 x 400 resolution means 680
dots across each of 400 lines.
Retrace
The blanked-out line traced by the scanning beam
of a picture tube as it travels from the end of any
horizontal line to the beginning of either the next
horizontal line or field. The beam is turned "off"
during retrace.
RGB (Red, Green, Blue)
Refers to the method of recording and generating
colors in a video system. On a television or color
monitor, colors are displayed as varying
intensities of red, green and blue dots. When red,
green and blue are all turned on high, white is
produced. When all dots are turned off, the base
color of the screen appears.
S-VHS
A high band video recording process for VHS that
increases picture quality and resolution capability.
S-VHS tape machines use a special output
terminal that allows separate output of luminance
(Y) and chrominance (C) picture information to
monitors equipped with S-image inputs.
Model 250 Service Manual
A-3
Glossary
A-4
S-Video
An image signal that has the luminance (Y)
information separated from chrominance (C)
information.
Saturated Color
1) A color as far from white, black or gray as it
can be (i.e., vermilion rather than pink). 2) A
display misadjustment that results in unnaturally
bright colors.
Scan
To scan, is to move across the image frame, one
line at a time, either to detect the image, as in an
analog or digital camera, or to refresh a CRTbased display.
Scan Line
One horizontal line in a graphics frame.
Scan Rate
The frequency or times per second one line is
scanned across an image display device such as a
CRT.
Synchronization
Also called “sync” for short. Pulses that time the
display of image information to the horizontal and
vertical CRT deflection. Signals included with the
source input that control the monitor's scan
circuits to properly time the lines and frames of a
picture.
Source input
The source of image and sync signals being input
into the projector. Typical source inputs are:
Computers, VCRs, Image generators, Satellite
feed.
Technician Remote
Remote control used during Model 250 setup and
adjustment. Alternative to Standard Remote.
Provides access to many of the setup functions by
direct keys instead of by menu maneuvering.
Throw Distance
Distance from the projector to the screen.
Underscan
Decrease raster size horizontally and vertically so
that all four edges of the picture are visible on the
display.
Vertical Height Pots
Potentiometers located on the Horizontal/Vertical
Deflection PCB. Used to adjust vertical height.
Vertical Resolution
The amount of detail that can be perceived in the
vertical direction. The maximum number of
Model 250 Service Manual
Glossary
alternating white and black horizontal lines that
can be counted from the top of the picture to the
bottom.
Vertical Scan Frequency
Vertical Scan
Reversal Jumper
The number of times per second a display image
is written or refreshed.
Reverses the image vertically for use with
mirror-bounced displays. Located on the Scan
Reversal PCB.
Vertical Synchronization
Frequency
The number of times per second a frame is
transmitted to a video display screen.
Xenon Arc Lamp
See Arc Lamp.
Model 250 Service Manual
A-5
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