MP8620 Multimedia Projector
Service Manual
3M Visual Systems Division
6801 River Place Boulevard
Austin, Texas 78726-9000
Printed in U.S.A.
©3M 6/99 78-6970-8988-2 Rev. A
3M Multimedia Projector MP8620
Table of Contents
MP8620 Table of Contents
1. Adjustments ...................................................................................................................................................1-1
1-1.
Overview ............................................................................................................................................1-1
1-2.
Static Control .....................................................................................................................................1-1
1-2-1. Static-Safe Work Environment .............................................................................................1-1
1-3.
Machine Identification .......................................................................................................................1-1
1-4.
Technician Tools ................................................................................................................................1-2
1-5.
Return to Default Settings ..................................................................................................................1-3
1-6.
Cleaning the LCD Panel.....................................................................................................................1-4
1-6-1. Checking for Dust .................................................................................................................1-4
1-6-2. Cleaning the Dust from LCD ................................................................................................1-4
1-7.
LCD Panel Alignment........................................................................................................................1-5
1-7-3. LCD Verification and Alignment.............................................................................................1-5
1-7-2. LCD Ribbon Cable Installation.............................................................................................1-5
1-7-3. LCD Ribbon Cable Installation.............................................................................................1-6
1-8.
Interface/Audio Board Synchronization.............................................................................................1-7
1-9.
Lamp Alignment ................................................................................................................................1-8
1-9-1. Check the Lamp Alignment ..................................................................................................1-9
1-9-2. Align the Lamp .....................................................................................................................1-9
1-10. Timer Information ............................................................................................................................1-10
1-10-1. Reset the Lamp Life Indicator.............................................................................................1-10
1-11. Image Adjustments...........................................................................................................................1-11
1-11-1. Adjusting the display resolution and brightness and contrast. ............................................1-11
1-11-2. Part 2 – Adjusting the tracking to remove vertical bands in the projection image..............1-12
1-11-3. Part 3 – Adjusting the Sync pixel frequency and scanning frequency. ...............................1-13
2.
Disassembly/Reassembly .............................................................................................................................2-1
2-1.
Overview ............................................................................................................................................2-1
2-2.
Required Tools ...................................................................................................................................2-1
2-3.
Steps for Removing Projector Components .......................................................................................2-1
2-3-1. Remove Top Cover ...............................................................................................................2-2
2-3-2. Remove EMI Shield..............................................................................................................2-3
2-3-3. Remove Lamp Assembly ......................................................................................................2-4
2-3-4. Remove Power Supply ..........................................................................................................2-7
2-3-5. Remove Power Distributor....................................................................................................2-8
2-3-6. Remove LCD Assembly........................................................................................................2-9
2-3-7. Remove Lens.......................................................................................................................2-11
2-3-8. Remove Audio Speakers .....................................................................................................2-12
2-3-9. Remove IR Receiver Board.................................................................................................2-13
3. Troubleshooting.............................................................................................................................................3-1
3-1.
Overview ............................................................................................................................................3-1
3-2.
Section Contents.................................................................................................................................3-1
3-3.
Direct Failure Troubleshooting Flow Charts......................................................................................3-1
3-3-1. Projector Does Not Power Up...............................................................................................3-2
3-3-2. Lamp Does Not Light............................................................................................................3-3
3-3-3. Projector Image Problem.......................................................................................................3-4
3-3-4. LCD Not Functioning ...........................................................................................................3-5
3-3-5. No Sound...............................................................................................................................3-6
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3M Multimedia Projector MP8620
3-4.
Table of Contents
General/Projection Image Troubleshooting .......................................................................................3-7
3-4-1. Image is Disturbed or Unstable .............................................................................................3-7
3-4-2. No Computer Image Projected..............................................................................................3-7
3-4-3. No Video Image Projected ....................................................................................................3-7
3-4-4. Mouse Does Not Work..........................................................................................................3-8
3-4-5. Image Off Center...................................................................................................................3-8
3-4-6. Cannot Get Entire Image on the Screen ................................................................................3-8
3-4-7. Washed Out Image................................................................................................................3-8
3-4-8. Humming Noise. Slowly Passing Horizontal Bars ...............................................................3-9
3-4-9. No Power. Power Shuts Off During Presentation .................................................................3-9
4. T heory and Diagrams ..................................................................................................................................4-1
4-1.
Overview ............................................................................................................................................4-1
4-2.
Theory of Operation ...........................................................................................................................4-1
4-2-1. Power Supply Circuit ............................................................................................................4-1
4-2-2. Video Input and AD Conversion...........................................................................................4-1
4-2-3. RGB Input and AD Conversion ............................................................................................4-2
4-3.
Color Theory ......................................................................................................................................4-3
4-3-1. Color......................................................................................................................................4-3
4-3-2. Electromagnetic Spectrum ....................................................................................................4-3
4-4.
LCD Structure Theory........................................................................................................................4-4
4-4-1. LCD Cells..............................................................................................................................4-4
4-4-2. How Light Passes Through An LCD ....................................................................................4-4
4-4-3. Example Projection ...............................................................................................................4-4
4-5.
Lamp Theory......................................................................................................................................4-5
4-6.
Keystone Correction...........................................................................................................................4-6
4-7.
Optical System Layout .......................................................................................................................4-7
4-8.
Connection Diagrams.........................................................................................................................4-8
4-9.
Wiring Diagrams ................................................................................................................................4-9
4-10. Internal Cabling Pinout Tables.........................................................................................................4-10
4-10-1. Interface Board Connector Locations .................................................................................4-10
4-10-2. Audio Board Connector Locations......................................................................................4-11
4-11. Computer/Video/Audio Connections ...............................................................................................4-12
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3M Multimedia Projector MP8620
Adjustments
1. Adjustments
1-1.
Overview
Make advanced adjustments to the MP8620 in a clean environment with minimal dust and positive pressure.
This section provides the advanced adjustment procedures needed to maintain a high quality projection image.
There is a specific order that adjustments are to be made and specific tools needed to complete each adjustment.
Important Note
Important: Complete advanced adjustments to a projector only when the
machine settings fall outside of the allowable tolerances for that
adjustment, or when instructed to do so by another procedure.
1-2.
Static Control
The circuit boards in the MP8620 are very sensitive to static energy. A simple static charge can ruin a circuit
board instantly. Because of this, it is essential that you complete all repairs in a static-safe work environment.
1-2-1. Static-Safe Work Environment
A properly grounded floor mat, table mat and adjustable wrist strap with grounding cord are needed for
complete static protection.
3M recommends any of the following workstation grounding kits:
3M™ Workstation Grounding Kit Model 8011
3M™ Workstation Grounding Kit Series 8020
3M™ Workstation Grounding Kit Series 8030
For your nearest distributor or to order, call 1-800-328-1368.
1-3.
Machine Identification
To avoid incorrect adjustments, verify the model and version of the projector prior to making any adjustments.
Different versions have unique adjustment requirements. The serial number for MP8620 is located on the back
of the projector.
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3M Multimedia Projector MP8620
1-4.
Adjustments
Technician Tools
Test Generator: 3M recommends the Quantum Data™ 801GX
Video Test Generator (shown to right) or Extron™ VTG200 Video
Test Generator be used for all advanced adjustment procedures. Use
to input a test pattern prior to adjustments.
External Power Supply: Used to check the audio interface PCB’s.
Service Interface Cable: Used to connect the original disassembled
power supply with the interface board.
LCD Alignment Tool: Used to check that the LCD alignment is at an 8 degree angle.
Backlight Light Source: Used to check the disassembled LCD unit without the original machine lamp source.
Voltmeter: Used to measure the voltage at particular test points. 3M recommends the Fluke™ model 87
Oscilloscope (100 MHz): Used to check the video signals horizontal and vertical synchronization and the video
board clock.
Torx Drivers: Use to remove mounting bolts.
White Silk Gloves: Used to keep skin oils away from the lamp and LCD panel.
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3M Multimedia Projector MP8620
1-5.
Adjustments
Return to Default Settings
1. Power down the projector and turn the main power switch to off.
Press and hold both the Enter button and the Down Arrow button on the control panel
2. Turn the main power switch to on. The default settings are restored and the following message appears:
Parameter Factory Settings Restored.
Resetting a projector to its default factory setting may resolve a “no input detected” error message for an RGB
or video input device.
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3M Multimedia Projector MP8620
1-6.
Adjustments
Cleaning the LCD Panel
Dust particles can accumulate on the glass covering the LCD panel causing spots on the projection image.
Periodic cleaning is necessary to maintain a high quality projection image.
1-6-1. Checking for Dust
Test for dust on the LCD panel by projecting a white image:
3. With the projector off, plug in the video test generator to an RGB terminal jack located on the back side of
the MP8620.
4. Use the video test generator to input the color White with a timing signal set to SVGA VESA (60).
Note
The voltage settings for each input color need to be programmed into the video
test generator. Refer to the video test generator user’s guide for further
assistance.
5. Turn the main power switch to the on position.
6. Look for dust particles on the projection image.
Note
Remove any dust from the outside of the projection lens with a lint-free cloth. If
dust remains on the projection image, the LCD panel needs to be cleaned.
1-6-2. Cleaning the Dust from LCD
If dust particles can be seen on your projection image:
1. Turn off the main power switch of the projector and unplug the power cord.
2. Remove the LCD module assembly. (Refer to the appropriate Disassembly/Reassembly procedures).
3. Use a dust blower or compressed air to blow air on the LCD panel. Do not exceed 40 PSI.
4. If dust is still visible wipe the LCD panel with a chamois swab or a lint-free cloth from the 3M LCD
cleaning kit.
Note
Use extreme care when cleaning any optics device. Special gelatin coatings can
be scratched very easily.
5. Use a lighted magnifier with a black background to check for streaks.
6. Replace the LCD panel, reassemble the projector and recheck the projection image for dust by projecting a
blank white image.
7. If dust still remains complete steps 1-6 again. If dust is gone, complete a LCD panel alignment.
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3M Multimedia Projector MP8620
1-7.
Adjustments
LCD Panel Alignment
Periodic LCD panel alignment is necessary to maintain a high quality projection image.
1-7-1. LCD Verification and Alignment
Use the LCD Alignment tool (DY-0205-1508-5) to verify the
8° angle of the LCD unit.
1. Measure the angle between the bottom and the assembly
surface of the LCD on the linkage side.
Alignment
Lever
2. If the angle is not 8°, reform the alignment lever to obtain
the proper 8° setting.
It may be needed to readjust the microswitch which is in
contact with to the LCD unit. This switch has to be activated
when the LCD is at the 8° angle.
1-7-2. LCD Ribbon Cable Installation
Installing a new LCD ribbon cable is done using the following steps:
1. Gently pull out the white plastic clamp on the LCD and interface board connectors to release the LCD
ribbon cable.
2. Insert one end of the new ribbon cable into the LCD connector. The blue side of the cable should be facing
up.
3. Insert the other end of the new ribbon cable into the interface board connector. The blue side of the cable
should be facing down.
4. Lock the white plastic clamps into place on both the LCD connector and the interface board connector.
5. Use the old cable as a pattern to place the appropriate bends in the new cable.
If a connector clamp is broken:
1. Order a complete connector (DY-0205-1512-7).
2. Remove the plastic portion from the new connector and replace the broken part.
3. If the connector can not be repaired in this way, the LCD or interface board may need to be replaced.
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Adjustments
1-7-3. LCD Ribbon Cable Installation
Installing a new LCD ribbon cable is done using the following steps:
1. Gently pull out the white plastic clamp on the LCD and Interface board connectors to release the LCD
ribbon cable.
2. Insert one end of the new ribbon cable into the LCD connector. The blue side of the cable should be facing
up.
3. Insert the other end of the new ribbon cable into the interface board connector. The blue side of the cable
should be facing down.
4. Lock the white plastic clamps into place on both the LCD connector and the Interface board connector.
5. Use the old cable as a pattern to place the appropriate bends in the new cable.
If a connector clamp is broken:
Order a complete connector (DY-0205-1512-7).
Remove the plastic portion from the new connector and replace the broken part.
If the connector can not be repaired in this way, the LCD or interface board may need to be replaced.
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3M Multimedia Projector MP8620
1-8.
Adjustments
Interface/Audio Board Synchronization
The interface board or the audio board must be in sync. If either one or both are changed, complete the
synchronization procedure.
1. Remove the power supply board using the procedure listed in the Disassembly/Reassembly section.
2. Remove the cooling fan and bracket by removing the two screws.
3. Remove three additional screws on the power supply base plate.
4. Tip up the base plate toward the lamp housing to remove it.
Power supply
board
Cooling fan bracket
Cooling fan
Power supply
base plate
5. Reconnect the power supply to the machine with the 3-pin connector, or reconnect the external power
supply (DY-0205-1509-3) to the machine with the 3-pin connector.
6. Connect the interface board to the power board with the Service Interface Cable (DY-205-1500-1).
7. Place a cover over the power supply board to prevent damage or injury.
Because the power supply board is fully energized in the next step, it is essential that a cover is placed over the
board to prevent injury.
8. Power up the projector.
9. Measure the voltage of pin 9 on the test block. This
connector is nearest the EPROM. Pin 1 is closest to
the EPROM. The voltage should be 3.4 Volts .01.
10. If the voltage reading of pin 9 on the test block is
outside the allowable tolerance, adjust the trim
potentiometer located in a small hole in the audio
board until the voltage reading is within tolerance.
11. When finished with the adjustment, reassemble
the projector.
Use extra care when replacing the power supply
base plate, the LCD cable can be damaged very
easily.
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3.4 Volts 0.1
Label
PCB
Trim
1-7
3M Multimedia Projector MP8620
1-9.
Adjustments
Lamp Alignment
A poorly aligned lamp can reduce the brightness or the uniformity of the projection image. To ensure that the
projector is producing the best possible image lamp alignment should be checked regularly.
1-9-1. Check the Lamp Alignment
1. With the projector off, remove the lamp assembly using
the procedure listed in the Disassembly/Reassembly
section.
2. Hold the lamp assembly and look through the condenser
at an angle perpendicular to the condenser lens.
3. The lamp should be aligned using the reflection image on
the lamp reflector. The image of the lamp should be
slightly above or slightly below the lamp.
Reflected image
of lamp slightly
below
4. If not, this position can be changed by turning
the two adjustment screws below the lamp
sockets.
Triplet lens
5. Verify the lamp alignment by powering up the
projector and viewing the image of the lamp on
the screen. This can be done by holding a triplet
lens in front of the projector lens .
6. Visually check to make sure the image of the lamp arc is positioned correctly:
Image of
arc
Correct lamp
alignment:
Image of
reflected
arc
Incorrect lamp
alignment:
b .
I m
a g e
o f
Image
b y
hof
i darc
d
l
hidden
by lamp
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c . I m a g e
Images
l a f m of
p arcs
a r c
f
too far
apart
dt o
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3M Multimedia Projector MP8620
Adjustments
1-9-2. Align the Lamp
1. With the projector off, adjust the lamp up or down by turning the two adjustment screws mounted on springs
under the lamp socket.
Note
If the arcs are too close, the lumen output will be reduced. If the arcs are to far
apart the image uniformity will be affected.
2. Verify the lamp alignment by powering up the projector and viewing the image of the lamp on the screen by
holding a triplet lens in front of the projector lens.
3. Repeat the above two steps until the lamp is aligned correctly.
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3M Multimedia Projector MP8620
Adjustments
1-10. Timer Information
A lamp life indicator is located under the Option sub-menu. If the indicator bar for the sub-menu item Lamp is
Green the lamp is good. When the bar turns red or the projection image appears dark, the lamp and air filter
should be replaced.
1-10-1. Reset the Lamp Life Indicator
1. Under the Option sub-menu select the sub-menu item Lamp and press Enter.
4. Follow the instructions in the Help Window.
5. Press the Enter button and the Up Arrow button on the control panel for confirmation.
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3M Multimedia Projector MP8620
Adjustments
1-11. Image Adjustments
1-11-1. Adjusting the display resolution and brightness and contrast.
1. Display the PC (RGB) input device projection image.
6. Boot up Microsoft Windows. Go to Control Panel and adjust the desktop background to an even black-andwhite raster. Or, display a projection image with black and white colors.
7. Press the Menu button on the projector to display the main menu.
8. Press the up/down Arrow buttons on the projector or the Control Stick on the remote control up/down to
highlight the Setup sub-menu.
9. Press the Enter button to select the Setup sub-menu. The current display resolution is displayed in the title
block of the Setup menu. For example 640 x 480. Change the display resolution if desired.
10. Confirm your selection by pressing the Enter button.
11. Press the up/down Arrow buttons on the projector or move the Control Stick on the remote control to
select the Palette sub-menu item.
12. Press the left/right Arrow buttons on the projector or the Control Stick on the remote control left/right to
reduce the chromatic resolution from the default that is 16.7 million colors to 64.
13. Press the up/down Arrow buttons on the projector or move the Control Stick on the remote control to
select the Pixels sub-menu item.
14. Press the left/right Arrow buttons on the projector or move the Control Stick on the remote control
left/right to increase or decrease the number of pixels in the display. Select 800 x 600.
15. Select the menu item Brightness and correct the setting so that white areas are projected with maximum
intensity.
16. Select the menu item Contrast and correct the setting so that the gray areas are clearly visible.
17. Press the Menu button to exit the sub-menu and return to the main menu.
18. A message will display in the help window asking you to confirm the changes made in the sub-menu. Press
Enter to confirm.
19. Press the Menu button to exit the main menu display and return to the projected image.
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3M Multimedia Projector MP8620
Adjustments
1-11-2. Part 2 – Adjusting the tracking to remove vertical bands in the projection image.
1. Test the tracking using a MS Excel spreadsheet projection image or equivalent. If vertical interference can
be seen, then the tracking needs adjustment.
2. Press the Menu button on the projector to display the main menu.
3. Press the up/down Arrow buttons on the projector or move the Control Stick on the remote control
up/down to highlight the Setup sub-menu.
4. Press the Enter button to select the Setup sub-menu.
5. Press the up/down Arrow buttons on the projector or move the Control Stick on the remote control to
select the Tracking sub-menu item.
6. Press the left/right Arrow buttons on the projector or move the Control Stick on the remote control
left/right to reduce the amount of interference.
7. The direction of adjustment is correct when the number of lines decreases. The setting is optimal when no
interference lines can be seen.
8. Press the Menu button to exit the sub-menu and return to the main menu.
9. A message will display in the help window asking you to confirm the changes made in the sub-menu. Press
Enter to confirm.
An automatic setting of tracking can be called up by pressing the Enter button. This may not work if the
projection image is a uniform pattern.
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3M Multimedia Projector MP8620
Adjustments
1-11-3. Part 3 – Adjusting the Sync pixel frequency and scanning frequency.
This adjustment removes any “fuzziness or flicker” in the projection image.
1. Press the Menu button on the projector to display the main menu.
2. Press the up/down Arrow buttons on the projector or move the Control Stick on the remote control
up/down to highlight the Setup sub-menu.
3. Press the Enter button to select the Setup sub-menu
4. Confirm your selection by pressing the Enter button.
5. Press the up/down Arrow buttons on the projector or move the Control Stick on the remote control to
select the Sync sub-menu item.
6. Press the left/right Arrow buttons on the projector or move the Control Stick on the remote control
left/right to reduce the amount of “fuzziness or flicker” in the projection image.
Before
After
An automatic setting of synchronization can be called up by pressing the Enter button.
7. Complete fine adjustments to the brightness and contrast settings if minor interference still remains.
Press the Menu button to exit the sub-menu and return to the main menu.
8. Complete fine adjustments to the brightness and contrast settings if minor interference still remains.
9. Press the Menu button to exit the sub-menu and return to the main menu.
10. A message will display in the help window asking you to confirm the changes made in the sub-menu. Press
Enter to confirm.
11. Press the Menu button to exit the main menu display and return to the projected image.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2. Disassembly/Reassembly
2-1.
Overview
Disassembly and reassembly of the MP8620 is done using the reference photographs and the step-by-step
procedures that follow. Many component disassembly steps build upon previous disassembly steps. Refer to
the previous disassembly steps as needed.
For general machine operation instructions including air filter or lamp replacement, refer to the Operator’s
Guide.
!
WARNING
To avoid electrical shocks, unplug projector power cord before performing any
maintenance to electrical components.
!
Caution
To avoid burns to fingers, allow projector lamp and internal projector components to
cool off prior to lamp removal or disassembly.
2-2.
Required Tools
An entire disassembly and reassembly can be completed with the following tools:
•
Phillips screwdriver (#1 magnetic long shaft)
•
Standard screwdriver (3/16 in. or ¼ in. blade)
2-3.
Steps for Removing Projector Components
Removal topics include:
•
Top cover
•
LCD Assembly
•
EMI shield
•
Lens
•
Lamp Assembly
•
Audio Speakers
•
Power Supply
•
IR Receiver board
•
Power Distributor
√ Note
If performing a complete disassembly, record lamp time.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-1. Remove Top Cover
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
1. Lift the two cover latches & lift the cover into the
projection position.
1
2
2. Carefully pry off two (2) cover hinges.
4
3. Lift rear of top cover up.
3
4. Slide top cover forward toward projection lens
5. Reassemble in reverse order.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-2. Remove EMI Shield
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Remove top cover.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
2
1
1. Remove two (2) screws.
2. Lift EMI shield up to remove.
3. Reassemble in reverse order.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-3. Remove Lamp Assembly
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
2
1. Remove two (2) screws from bottom of base.
2. Depress lock tab and slide cover to remove.
1
3
3. Lift latch to release lamp panel and lower panel to the
open position.
√ Note
Do not touch lamp glass with fingers. Oil from
fingers can reduce lamp life.
4. Release wire from wire holder.
5. Return lamp panel to the closed position.
6. Remove EMI shield. (See Section 2-3-2.)
4
5
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3M Multimedia Projector MP8620
Disassembly/Reassembly
8
7. Remove two (2) screws securing lamp housing cover.
7
8. Lift the front of the lamp housing cover up then slide
it forward to remove.
11
9. Remove the IR filter. Notice the position of the filter
for reassembly. The fins point downward and out.
10
9
10. Remove light shield by pulling it up and out.
11. Disconnect two (2) wire connectors from the
thermostat.
12
12. Loosen two (2) screws on the white lamp leads and
carefully disconnect wires.
12
13
13. Remove one (1) screw to disconnect two (2) ground
wires.
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3M Multimedia Projector MP8620
14. Feed lamp wire leads through front of lamp housing.
15. Remove four (4) Torx head screws to free lamp
assembly. Carefully lift lamp assembly out of
projector body.
Disassembly/Reassembly
14
15
15
16. Reassemble in reverse order.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-4. Remove Power Supply
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
Remove the EMI shield.
1. Remove the lamp wire leads from the power supply
board at the fan end. These leads connect to the lamp
ignitor.
1
2. Disconnect the ten-pin PCB Interface connector.
3. Disconnect the three-pin power connector.
4. Disconnect all fan cables (four (4) connectors in a
block) that are opposite the cooling fan. These cables
are connected in parallel and do not need to be
reconnected in the exact same connector.
5. Remove one (1) screw to release two ground wires.
6. Remove three (3) phillips screws to release power
supply.
5
2
4
3
6
7. Reassemble in reverse order.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-5. Remove Power Distributor
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
2
Remove lamp assembly and power supply.
1. Remove three (3) screws securing cover.
2. Lift edge of cover toward front of machine first and
then remove.
1
3. Disconnect three (3) cable connectors.
4. Disconnect two (2) ribbon cables.
4
4
3
3
5
7
5. Remove one (1) screw to disconnect ground.
6. Disconnect two (2) ribbon cables.
7. Remove two (2) screws (one on each side).
8. Remove power distributor.
9. Reassemble in reverse order.
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-6. Remove LCD Assembly
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
Remove the lamp and the power supply.
2
1. Remove three (3) screws securing cover.
2. Lift edge of cover toward front of machine first and
then remove.
1
3. Disconnect LCD ribbon cable.
4
4. Feed LCD ribbon cable through EMI ferrite.
3
5. Remove two (2) cable ties.
5
6. Remove two (2) screws from left side LCD assembly
bracket.
6
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3M Multimedia Projector MP8620
7. Remove two (2) screws from right side LCD
assembly pivot bracket.
Disassembly/Reassembly
9
8. Remove one (1) e-ring.
9. Remove LCD assembly.
10. Reassemble in reverse order.
7
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-7. Remove Lens
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
!
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
Remove the top cover.
1. Remove four (4) screws (two on each side) to release
the lens.
2. Reassemble in reverse order.
 3M 1999
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-8. Remove Audio Speakers
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
!
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
Remove the lamp assembly and power supply.
2
1. Remove three (3) screws securing cover.
2. Lift edge of cover toward front of machine first and
then remove.
1
3. Disconnect two (2) cable connectors.
3
4. Remove four (4) screws (two on each side) from left
and right speaker brackets.
5. Remove speakers.
4
6. Reassemble in reverse order.
5
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3M Multimedia Projector MP8620
Disassembly/Reassembly
2-3-9. Remove IR Receiver Board
!
!
WARNING
To avoid electrical shocks, unplug projector
power cord before performing any maintenance
to electrical components.
Caution
To avoid burns to fingers, allow projector lamp
and internal projector components to cool off prior
to lamp removal or disassembly.
Remove the top cover.
1. Disconnect one (1) cable connector.
2. Remove one (1) screw from IR receiver board.
2
3. Remove IR receiver board.
4. Reassemble in reverse order.
1
 3M 1999
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3M Multimedia Projector MP8620
Troubleshooting
3. Troubleshooting
3-1.
Overview
Troubleshooting is necessary to isolate problems with the MP8620. This section contains troubleshooting flow
charts and a general problems section.
3-2.
Section Contents
Direct Failure Troubleshooting Flow Charts
General/Projection Image Troubleshooting
3-3.
Direct Failure Troubleshooting Flow Charts
The troubleshooting flow charts listed in this section start with the basics and move forward. They are designed
to be used for solving direct failure problems.
The following problems can be resolved using the troubleshooting flow charts:
Projector Does Not Power Up
Lamp Does Not Light
Projection Image Problems
LCD Not Functioning
No Sound
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3-1
3M Multimedia Projector MP8620
Troubleshooting
3-3-1. Projector Does Not Power Up
Projector Does
Not Power Up
Yes
Is the lamp
access door
closed
completely?
No
Close the lamp
access door.
Yes
Is the LCD in
the projection
position?
No
Close top cover,
reopen
completely.
Yes
Is the LCD
switch fully
engaged?
No
Adjust switch
position, replace
switch if faulty.
Yes
Is the fuse on the
power supply
functioning
properly?
No
Replace fuse.
Yes
Replace the power
supply
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3M Multimedia Projector MP8620
Troubleshooting
3-3-2. Lamp Does Not Light
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3-3
3M Multimedia Projector MP8620
Troubleshooting
3-3-3. Projector Image Problem
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3M Multimedia Projector MP8620
Troubleshooting
3-3-4. LCD Not Functioning
LCD Not
Functioning?
Yes
Does the menu
screen appear
when the
projector is
powered on?
No
Refer to "Projector
Does Not Power
Up".
Yes
Does the input
device send
the video signal
properly?
No
Check input
device and
cabling.
Yes
Is the LCD
cable properly
functioning?
No
Replace pinched
or broken ribbon
cables.
Yes
Is the interface
board
powering the
LCD?
Yes
No
Check connections.
Replace interface
board if needed.
Replace the LCD
unit.
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3M Multimedia Projector MP8620
Troubleshooting
3-3-5. No Sound
No Sound?
Yes
Is the audio
input device
connected
properly?
No
Check input
device cabling and
input device.
Yes
Is the speaker
in good
physical
condition?
No
Yes
Are the speaker
wires connected
and functioning?
Replace speaker.
No
Reconnect,
repair, or replace
wires as needed.
Yes
Is the audio
board receiving
power from the
power supply?
Yes
No
Check connections
and cabling.
Replace the audio
board.
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3M Multimedia Projector MP8620
3-4.
Troubleshooting
General/Projection Image Troubleshooting
Past experience has shown the following problems are most common:
3-4-1. Image is Disturbed or Unstable
Probable causes are:
Wrong sync setting
Wrong tracking value
Possible solutions are:
Set to factory default setting (refer to Appendix C-2).
Change Sync setting in the Setup menu for optimum performance.
For vertical interference stripes, change the Tracking in the Setup menu for optimum performance.
3-4-2. No Computer Image Projected
Message No input detected is shown.
Probable causes are:
Loose cable.
No power to computer.
Wrong synchronization mode.
Possible solutions are:
Check and secure cable connections.
Turn on computer.
Adjust synchronization mode of the projector to the synchronization mode of the computer via Option
menu.
3-4-3. No Video Image Projected
Probable causes are:
No signal from video source.
Check and secure cable connections.
Check video picture on TV.
Possible solutions are:
Check and secure cable connections.
For PS/2 and ADB (Apple) mouse, a special adapter is necessary.
Only use adapters from the original manufacturer.
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3M Multimedia Projector MP8620
Troubleshooting
3-4-4. Mouse Does Not Work
Probable causes are:
Loose cable.
Wrong connection.
Wrong power up sequence.
Possible solutions are:
The mouse emulation operates correctly only if the correct power up sequence has been used.
3-4-5. Image Off Center
Probable causes are:
Image position
Center image with the arrow keys of the control panel or the disc pad on the remote control.
If vertical interference stripes occur, change the Tracking value in the Setup menu for optimum
performance.
3-4-6. Cannot Get Entire Image on the Screen
Probable causes are:
Wrong Tracking value.
Compatibility problem.
Wrong pixel setting.
Possible solutions are:
Refer to the documentation of your graphic card.
The projector supports the resolutions that can be found under Pixel in the Setup menu.
Adjust the Pixel setting in the Setup menu to the resolution of the video mode output from the computer
graphic card.
3-4-7. Washed Out Image
Probable causes are:
Wrong Contrast setting.
Wrong Brightness setting.
Possible solutions are:
Change Contrast setting in the Setup menu. The bar should be in the middle position.
Lower Brightness setting in the Setup menu. Choosing Brightness and pressing Enter performs an automatic
adjustment.
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3M Multimedia Projector MP8620
Troubleshooting
3-4-8. Humming Noise. Slowly Passing Horizontal Bars
Probable causes are:
Signal sources are connected to different power sources.
VCR connected to aerial system and to projector.
Bad signal.
Possible solutions are:
Locate the source of disturbance. Disconnect the sources one after another from the projector. Connect all
sources to a common power source.
Remove antenna connection from VCR. If the disturbance disappears, use a bypass filter (isolating
transformer) to connect the antenna to the VCR.
Try different input source.
3-4-9. No Power. Power Shuts Off During Presentation
Probable causes are:
Power switch OFF.
Projector overheated.
Possible solutions are:
Turn on Power switch to projector.
Remove any objects blocking ventilation and allow projector to cool down. Power will return and projector
will be in Standby mode.
MP8620 Message Table
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3M Multimedia Projector MP8620
Theory and Diagrams
4. Theory and Diagrams
4-1.
Overview
In order to truly understand what is taking place when making advanced projector adjustments, the following
concepts must be introduced and explained. An understanding of these principles increases your efficiency when
making advanced projector adjustments. The diagrams in this section assist you in finding the pin locations,
connectors and wiring during troubleshooting.
4-2.
Theory of Operation
Use the projector circuitry diagrams as a reference when reading the topics in this section.
4-2-1. Power Supply Circuit
When the main power switch is on and the 110V AC power is supplied, two DC power circuits are energized.
The AC power passes through a filter then on to the ballast where the AC voltage changes to DC voltage and is
split. High voltage DC current is sent to the lamp where it will have six tries to light. Low voltage DC current is
sent to the power unit circuit then to the Micro processor to power the rest of the projector.
4-2-2. Video Input and AD Conversion
There are two sets of video inputs. Switching between them is done using the input button on the top of the
projector or the Video1/2 button on the remote control.
Signal Board
The video signal passes though the video signal selector then to the comb filter where it is split into the chroma
signal (C). It is then sent to the RGB/video selector and the luminance (Y) signal is sent to the sync selector.
Driver Board
The signal passes through another selector before the AD converter. The analog signal is changed to a digital
signal and passes though the on screen display. The gate array is where a smoothing affect and resizing takes
place. The signal is then changed back to analog and sent to the video amplifier/inversion amplifier. The
luminance signal (Y) information passes through the gate array and timing generator. A PLL circuit generates
the sampling pulse for the AD converter and is dependent upon the detection of vertical and horizontal sync
pulses. The two signals are output though the video amplifier, where the sample/hold and video rotation take
place before each LCD receives the appropriate information.
3M 1999
4-1
3M Multimedia Projector MP8620
Theory and Diagrams
4-2-3. RGB Input and AD Conversion
There are two sets of RGB inputs. Switching between them is done using the input button on the top of the
projector or the RGB1/2 button on the remote control.
Signal Board
The RGB signal goes through a RGB1/2 signal selector then the chroma signal (C) information is sent to the
video/RGB selector and the luminal signal (Y) information is sent to sync selection.
Driver Board
Refer to driver board information for video.
RGB Out
RGB out simply takes the information in its analog state and passes it through an amplifier to the terminal out.
Additional electronic image smoothing occurs in the gate array of the MP8610.
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4-2
3M Multimedia Projector MP8620
4-3.
Theory and Diagrams
Color Theory
An understanding of color theory provides a background for making the convergence and white balance
adjustments discussed in Section 6.
4-3-1. Color
Color is a visual sensation that involves three
elements— a light source, an object, and a viewer.
Light is reflected and modified by an object, then
reaches the receptors in our eyes and is interpreted by
our brains into what we know as color.
Each color has its own measurable wavelength or
combination of wavelengths. The wavelengths of light
are not colored, but produce the sensation of color.
4-3-2. Electromagnetic Spectrum
All wavelengths of light are part of the
electromagnetic energy spectrum. The spectrum is a
continuous sequence of energy waves that vary in
length from short to long. Visible light, the
wavelength that our eyes can detect, is only a small
portion of the entire spectrum. At one end of the
visible spectrum are the short wavelengths of light
we perceive as blue. At the other end of the visible
spectrum are the longer wavelengths of light we
perceive as red. All other colors are found
somewhere along the spectrum between blue and red.
3M 1999
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3M Multimedia Projector MP8620
4-4.
Theory and Diagrams
LCD Structure Theory
An understanding of LCD Structure theory provides a background for making the convergence adjustments
discussed in section 6.
LCD is the acronym for Liquid Crystal Display. The three LCD panels (Red, Green, Blue) in the MP8610 are a
1.3” square, poly-silicon design. Each LCD panel is composed of a layer of liquid crystal cells, electrodes, and
glass.
4-4-1. LCD Cells
Each cell is composed of long, rod shaped molecules that react to an electrical charge. In their normal state, the
molecules form a spiral. When an electrical charge is applied, the molecules align themselves allowing the light
to pass through the pixels. Shades of gray are obtained by inputting voltages that fall between full off (no
voltage) and full on (full voltage). The cells are refreshed at the speed of 1/60th of a second and are sensitive to
high temperatures.
4-4-2. How Light Passes Through An LCD
Polarized light entering the cells from the rear is aligned so that it will pass the light through the polarizer on the
other side. Patterned transparent electrodes on the inner surfaces of the glass form an addressing system that
creates a distinct electric field for each pixel. The light that was not aligned as it passed through the liquid
crystal cell is blocked.
4-4-3. Example Projection
If 100% of the red light is emitted through the red LCD panel and 50% of the green light makes it through the
green LCD panel and the blue light is blocked entirely, a light brown screen is projected.
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3M Multimedia Projector MP8620
4-5.
Theory and Diagrams
Lamp Theory
The MP8620 with a DC 400 watt metal halide bulb is capable of producing 450+ lumens of uniform brightness
across the entire projection image.
The metal halide bulbs should never be touched. When oil from your skin touches the bulb, it provides a focal
point for the lamp energy. The lamp burns hotter at that location and eventually burns through the bulb
prematurely.
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3M Multimedia Projector MP8620
4-6.
Theory and Diagrams
Keystone Correction
A correct projection image on the MP8620 should be
square and in focus. A projection image that is wider at
the top and has a softened focus has keystoning.
Keystoning is visible on the MP8620 when the
projection to screen angle is greater than sixteen
degrees. As the front of the projector is raised the
projection angle increases. At sixteen degrees the
projection image is still square and in focus, at nineteen
degrees keystoning can be seen.
The MP8620 is keystone corrected at a ratio of 3.9 to 1
to provide a square focused image as shown. Restated,
for every 3.9 feet of projection distance the image is
raised 1 foot. This feature allows for 80% of the
projection image to appear above the lens center with
only 20% appearing below.
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3M Multimedia Projector MP8620
4-7.
Theory and Diagrams
Optical System Layout
Notice that the optics module is composed of a lamp, a fresnel lens, and an LCD panel.
Condenser
Lens
Cold
Mirror
IR and
UV Light
Lamp
Lamp
Reflector
Hot
Mirror
Lamp Side
Fresnel
Lens Side
Fresnel
Lens
LCD
IR Light
UV Light
Polarizer
3M 1999
Lamp
Projects light.
Fresnel Lens
Magnifies the projection image.
Polarizer
Allows light waves, at the right angle, to pass
through
Hot Mirror
Heat management device that passes the light
and reflects heat, IR and UV light.
Cold Mirror
Reflector
Heat management device that reflects the light
and passes heat, IR and UV light.
LCD Panel
Positions the liquid crystal cells that form an
image.
4-7
3M Multimedia Projector MP8620
4-8.
Theory and Diagrams
Connection Diagrams
Electrical diagrams provide a visual representation of how the projector circuitry is connected.
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4-8
3M Multimedia Projector MP8620
4-9.
Theory and Diagrams
Wiring Diagrams
Wiring diagrams provide a visual representation of how the projector is wired.
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4-9
3M Multimedia Projector MP8620
Theory and Diagrams
4-10. Internal Cabling Pinout Tables
The pinout tables listed in this section are designed to assists in solving internal cable failure problems.
4-10-1. Interface Board Connector Locations
Power Supply Connector (J10)
Pin 1 of the connector is the black cable and pin 10 of the connector is the red cable.
1-2
3
4
5
6-7
8
9
10
3M 1999
5 Volt
-5 Volt
+12 Volt
-12 Volt
Ground
Lamp on = 5Volt (TTL high) Lamp off = 0 Volt (TTL Low
Dimmer Standard = 0 Volt (TTL low) Economy = 5 Volt
Fan on= 5Volt (TTL high) Fan off = 0 Volts(TTL low)
4-10
3M Multimedia Projector MP8620
Theory and Diagrams
4-10-2. Audio Board Connector Locations
Video Out (J1)
This connector joins the audio and interface boards.
Video In (J2)
Allows for video input from the interface board to the audio board.
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3M Multimedia Projector MP8620
Theory and Diagrams
4-11. Computer/Video/Audio Connections
The information provided in this section is for reference purposes. Each type of cable is shown with a pinout
diagram.
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3M Multimedia Projector MP8620
3M 1999
Theory and Diagrams
4-13
Important Notice
All statements, technical information, and recommendations related to 3M’s products are based on information believed to be reliable, but the accuracy or
completeness is not guaranteed. Before using this product, you must evaluate it and determine if it is suitable for your intended application. You assume
all risks and liability associated with such use. Any statements related to the product which are not contained in 3M’s current publications, or any contrary
statements contained on your purchase order shall have no force or effect unless expressly set forth in a written agreement signed by an authorized officer
of 3M.
Warranty and Limited Remedy. This product will be free from defects in material and manufacture for a period of two years from the date of
purchase. 3M MAKES NO OTHER WARRANTIES INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. If this product is defective within the warranty period stated above, your exclusive remedy shall
be, at 3M’s option, to replace or repair the 3M product or refund the purchase price of the 3M product.
Limitation of Liability. Except where prohibited by law, 3M will not be liable for any loss or damage arising from this 3M product, whether
direct, indirect, special, incidental or consequential regardless of the legal theory asserted.
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e-mail:
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