CHAPTER 1 GENERAL ADJUSTMENTS

SAFETY INSTRUCTIONS

WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRECAU-

TION” AND “PRODUCT SAFETY NOTICE” INSTRUCTIONS BELOW.

X-RAY RADIATION PRECAUTION

1. Excessive high voltage can produce potentially hazardous

X-RAY RADIATION. To avoid such hazards, the high voltage must not be above the specified limit. The nominal value of the high voltage of this receiver is (A) kV at zero beam current (minimum brightness) under a 120V AC power source. The high voltage must not, under any circumstances, exceed (B) kV.

Refer to table-1 for high voltage (A), (B).

(See SETTING & ADJUSTING DATA on page 19)

Each time a receiver requires servicing, the high voltage should be checked following the HIGH VOLTAGE CHECK procedure in this manual. It is recommended that the reading of the high voltage be recorded as a part of the service record. It is important to use an accurate and reliable high voltage meter.

2. This receiver is equipped with a Fail Safe (FS) circuit which prevents the receiver from producing an excessively high voltage even if the B+ voltage increases abnormally. Each time the receiver is serviced, the FS circuit must be checked to determine that the circuit is properly functioning, following the FS CIRCUIT CHECK procedure in this manual.

3. The only source of X-RAY RADIATION in this TV receiver is the picture tube. For continued X-RAY RADIATION protection, the replacement tube must be exactly the same type tube as specified in the parts list.

4. Some part in this receiver have special safety-related characteristics for X-RAY RADIATION protection. For continued safety, parts replacement should be undertaken only after referring to the PRODUCT SAFETY NOTICE below.

SAFETY PRECAUTION

WARNING : Service should not be attempted by anyone unfamiliar with the necessary precautions on this receiver. The following are the necessary precautions to be observed before servicing this chassis.

1. An isolation Transformer should be connected in the power line between the receiver and the AC line before any service is performed on the receiver.

2. Always discharge the picture tube anode to the CRT conductive coating before handling the picture tube. The picture tube is highly evacuated and if broken, glass fragments will be violently expelled. Use shatter proof goggles and keep picture tube away from the unprotected body while handling.

3. When replacing a chassis in the cabinet, always be certain that all the protective devices are put back in place, such as; non-metallic control knobs, insulating covers, shields, isolation resistor-capacitor network etc.

4. Before returning the set to the customer, always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals, screwheads, metal overlays, control shafts etc. to be sure the set is safe to operate without danger of electrical shock. Plug the AC line cord directly into a 120V AC outlet (do not use a line isolation transformer during this check). Use an AC voltmeter having 5000 ohms per volt or more sensitivity in the following manner:

Connect a 1500 ohm 10 watt resistor, paralleled by a 0.15

µF, AC type capacitor, between a known good earth ground

(water pipe, conduit, etc.) and the exposed metallic parts, one at a time. Measure the AC voltage across the combination of 1500 ohm resistor and 0.15

µF capacitor. Reverse the AC plug at the AC outlet and repeat AC voltage measurements for each exposed metallic part. Voltage measured must not exceed 0.3 volts rms. This corresponds to 0.2 milliamp. AC. Any value exceeding this limit constitutes a potential shock hazard and must be corrected immediately.

Good earth ground such as a water pipe, conduit, etc.

PRODUCT SAFETY NOTICE

AC VOLTMETER

0.15

µF

1500 ohm

10 watt

Place this probe on each exposed metallic part.

Many electrical and mechanical parts in this chassis have special safety-related characteristics. These characteristics are often passed unnoticed by a visual inspection and the protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Replacement parts which have these special safety characteristics are identified in this manual and its supplements; electrical components having such features are identified by the international hazard symbols on the schematic diagram and the parts list.

Before replacing any of these components, read the parts list in this manual carefully. The use of substitute replacement parts which do not have the same safety characteristics as specified in the parts list may create shock, fire, X-ray radiation or other hazards.

– 3 –

CRT ASSEMBLY REPLACEMENT AND MOUNTING

CAUTION : DO NOT LOOSEN THE HEX HEAD BOLTS WITH SPRINGS (12 PCS), BECAUSE THOSE ARE FOR

SEALING OF CRT COOLANT.

R G B

8 o’clock

4 o’clock

Attention Serviceman

The Hex Head

Bolts with

Springs. (see sketch) used on

CRT assembly, are “NOT”

Adjustment Screws

DO NOT LOOSEN-FLUID

LEAKAGE WILL OCCUR.

4 Screws

4 Screws

Lens Assembly

CRT Assembly

CRT Anode Cap Assembly

S.V.M. Coil

CRT DRIVE Board

CRT Mounting

Deflection Yoke and Conver Yoke

Lens and Neck Components View

– 4 –

TO REMOVE CRT (Same procedure for R, G, B)

1. Remove CRT DRIVE Board, S. V. M. COIL and

DEF. YOKE from CRT.

2. Remove Lens Assembly.

3. Detach CRT Anode Cap from CRT.

4. Remove CRT Assembly from CRT Mounting.

CRT REPLACEMENT (Same procedure for R, G, B)

Reverse the removal procedures except the followings.

1. Anode Cable should be replaced with new one.

See “SERVICING PRECAUTIONS” shown below.

2. Install silicon (T461B) to the CRT, replace the Anode cable and put enough silicon again on around the Anode Cap as illustrated.

CAUTION: Align the Anode cable as illustrated on page

4.

ADJUSTING PROCEDURE IN REPLACING CRT

1. R.G.B. FOCUS ADJUSTMENT (page 7.)

2. PICTURE TILT ADJUSTMENT (page 7.)

3. USER CONVERGENCE CENTER CHECK

(See owner's manual.)

4. CENTERING ADJUSTMENT (page 7.)

5. CONVERGENCE ADJUSTMENT (page 14.)

6. WHITE BALANCE ADJUSTMENT (page 13.)

Adjustments are complete.

Silicon

(On shaded area)

TSE3843W #23960136

Anode Cap

2 ~ 5 mm

15 ~ 25 mm

SERVICING PRECAUTIONS

■ Do not use a magnetized screw driver for screws of Deflection Yoke and Velocity Modulation Coil to avoid magnetization of electron gun.

Magnetization of electron gun will degrade basic function and result in unbalance of right and left shift of user static convergence, and result in no variable quantity.

■ When replacing the anode cap assembly (CRT) or anode lead assembly (F.B.T.), remove the anode lead holder from old one and attach the holder again to new anode lead.

■ Check the point of anode lead in a straight line, if it is winding, please revise it.

Screw for

D.Y

Screw for SVM coil

Anode lead holder

– 5 –

WARNING : BEFORE SERVICING THIS CHASSIS, READ THE “X-RAY RADIATION PRECAUTION”, “SAFETY PRE-

CAUTION” AND “PRODUCT SAFETY NOTICE” ON PAGE 3 OF THIS MANUAL.

PICTURE TUBE COMPONENTS ADJUSTMENT

DESCRIPTION OF NECK COMPONENTS

�

�

� Deflection yoke and convergence yoke

The position on the neck is required most front

(CRT funnel side) and the screw is fastened after rotating yoke adjusting picture tilt.

� Centering magnet

After adjusting picture tilt, picture position is finally fixed by this magnet.

In order to get maximum margin of user convergence control for center of screen, this magnet have to be used for center convergence adjustment.

PREPARATION

Operate the receiver for at least 5 minutes.

– 6 –

R, G, B FOCUS ADJUSTMENT

1. Before adjusting the R, G, B FOCUS, remove the 4 screws of Lens Assembly which is fixed on the CRT Assembly.

(See page 4.)

Then turn around the Lens Assembly by 180˚ to adjust the fastening screw (Fig. a) and fasten the 4 screws to secure Lens Assembly.

2. Select the adjustment mode. (See page 10.)

3. Press “7” button to display the built-in cross-hatch.

4. Press “0” and “RTN” buttons to make the picture a single

Red color.

100 button ................ to erase Red color

0 button .................... to erase Green color

RTN button .............. to erase Blue color.

5. Loosen the fasten screw and adjust Red lens focus to best focusing point of picture center. Then fasten the screw.

(See Fig. a.)

TILT ADJUSTMENT

Rotate R, G, B deflection yoke so that picture becomes horizon, then fasten screw.

CENTERING ADJUSTMENT

1. Stretch a thread between two center of screen edge (top and bottom, left and right).

Fig. a

6. Adjust FOCUS VR “R” of FOCUS PACK to find best focusing point of picture center.

7. Repeat steps 3 to 5 for Green and Blue colors.

2. Receive NTSC.

Then select SERVICE MODE. (See Page 10.)

3. Select CONVERGENCE ADJUSTING mode, and press

"7" button to display the built-in cross-hatch pattern.

Move Cursol and recognize horizontal line indicated Y:4.

This line is vertical center. Push "9" button to display the vertical stripes, and recognaize horizontal center.

4. Perform VCEN adjustment. (See page 12.)

5. Adjust G centering magnet so that the cross-bar pattern center comes to screen center.

6. Perform HEIGHT adjustment . (See page 13.)

7. Perform VERT. LINEARITY adjustment.

8. Perform WIDTH adjustment. (See page 12.)

9. Check whole quality of green line.

10. Adjust R, B centering magnet so that the cross-bar pattern center comes to screen center.

– 7 –

LOCATION OF SCREEN AND FOCUS VR’S

Speaker grille

R G B

SCREEN VR

FOCUS VR

– 8 –

REPLACEMENT OF THE CRT

Service parts are provided for each R, G and B.

The contents of the parts are as follows.

R

23008174

G

23008175

HITACHI

CRT

REPLACEMENT OF HIGH VOLTAGE CABLE

ANODE LEAD

RUBBER BOOT

LEAD HOLDER

B

23008176

1. When replacing Anode Lead or Anode Cap with new one, remove Lead Holder from old lead as shown in figure below, and put it on new lead. Do not throw away Lead

Holder.

NOTE : THE LEAD HOLDER IS ATTACHED TO TPA5007

(Z450), BUT IS NOT ATTACHED TO ANODE

LEAD AND ANODE CAP. RUBBER BOOT IS AT-

TACHED TO ANODE LEAD AND ANODE CAP.

2. Detaching Lead Holder

RUBBER BOOT

OLD

ANODE LEAD or

ANODE CAP

Fig. a

Z450 TPA5007

LOCK LEAD HOLDER Cut here rubber boot and lead together to detach Lead Holder.

Fig. b

– 9 –

1. ENTERING TO SERVICE MODE

1) Press MUTE button twice on Remote Control.

SERVICE MODE

2) Press MUTE button again to keep pressing.

3) While pressing the MUTE button, press MENU button on TV set.

S

MUTE

2. DISPLAYING THE ADJUSTMENT MENU

1) Press MENU button on TV.

Service mode

S

Press

Press

Adjustment mode

Item

Data

(Service mode display)

3. KEY FUNCTION IN THE SERVICE MODE

The following key entry during display of adjustment menu provides special functions.

Screen adjustment mode ON/OFF:

Selection of the adjustment items :

Change of the data value :

Adjustment menu mode ON/OFF :

TV (ANT)/VIDEO button (on TV)

Channel s/t (on TV or Remote)

Volume s/t (on TV or Remote)

MENU button (on TV)

Initialization of the memory (QA02) : RECALL+Channel button on TV (s)

Initialization of the self diagnostic data: RECALL+Channel button on TV (t)

“RCUT” selection :

“GCUT” selection :

“BCUT” selection :

“SCNT” selection :

“SCOL” selection :

“TNTC” selection :

Convergence adj :

Self diagnostic display :

1 button

2 button

3 button

4 button

5 button

6 button

7 button

9 button

– 10 –

4. SELECTING THE ADJUSTING ITEMS

1) Every pressing of CHANNEL s button in the service mode changes the adjustment items in the order of table-2.

(t button for reverse order)

Refer to table-2 for preset data of adjustment mode.

(See SETTING & ADJUSTING DATA on page 19)

5. ADJUSTING THE DATA

1) Pressing of VOLUME s or t button will change the value of data in the range from 00H to FFH. The variable range depends on the adjusting item.

6. EXIT FROM SERVICE MODE

1) Pressing POWER button to turn off the TV once.

■

INITIALIZATION OF MEMORY DATA OF QA02

After replacing QA02, the following initialization is required.

1. Enter the service mode, then select any register item.

2. Press and hold the RECALL button on the Remote, then press the CHANNEL s button on the TV. The initialization of QA02 has been complated.

3. Check the picture carefully. If necessary, adjust any adjustment item above.

Perform “Programming Channel Memory” on the owner's manual.

CAUTION: Never attempt to initialize the data unless QA02 has been replaced.

7. SELF DIAGNOSTIC FUNCTION

1) Press “9” button on Remote Control during display of adjustment menu in the service mode.

The diagnosis will begin to check if interface among IC’s are executed properly.

2) During diagnosis, the following displays are shown.

�

�

�

�

�

�

�

�

SELF CHECK

NO. 23 * * * * * *

POWER : 000

BUS LINE : OK

BUS CONT : OK

BLOCK : MAIN SUB

SET ID : 01

EEP VER : 02

OPT1 : 05 OPT2 : 70

� Part number of microprocessor (QA01)

� Operation number of protection circuit (current limiter) . . . . “000” is normal.

� BUS line check

“OK” ................... Normal

“SCL-GND” or “NG” ........... SCL-GND short circuit

“SDA-GND” or “NG” ........... SDA-GND short circuit

“SCL-SDA” or “NG” ............ SCL-SDA short circuit

� BUS line ACK (acknowledge) check

“OK” ..................... Normal

Display of Location Number . . . . NG

(Display example)

“QA02 NG”, “H001 NG”, “Q501 NG” etc.

� Sync. signal check

Note: The indication of failure place is only one place though failure places are plural. When repair of a failure place finishes, the next failure place is indicated. (The order of priority of indication is left side.)

Green display ..... Normal

Red display ........ NG

MAIN ........ Main sync

SUB .......... Sub sync (when turn on the PIP)

� ID code for TV Set

� Version of "EEP"

� Data for "OPT"

– 11 –

ELECTRICAL ADJUSTMENT

ITEM

ƒH

(free-running frequency of Hor.

oscillator)

VERTICAL POSI-

TION (VCEN)

ADJUSTMENT PROCEDURE

1. Receive NTSC signal.

2. Short the terminal “TP +9V ” and the terminal “ TP (Free run) ” on the signal board with a jumper wire.

3. Connect the probe of frequency counter to the lead of R426 and GND.

4. Adjust the frequency to “33.75

±0.2 kHz” by turning R4034 on DPC Board.

5. Disconnect the shorted wire, then confirm that the picture is synchronized.

1. Receive NTSC signal.

2. Connect he probe of digital voltmeter to TP-V and TP-G on SIGNAL Board.

3. Call up the adjustment mode display, then select the item VCEN.

4. Press the VOLUME s or t button to get the voltage 0±10 mV.

PICTURE POSITION

(HPOS)

1. Receive NTSC signal.

2. Call up the adjustment mode display.

3. Select the item “HPOS”, and adjust the data to “80H”.

4. Adjust the picture position alternately by turning CENTERING MAGNETS for proper picture position.

5. Check the picture with off-air signal.

WIDTH

(WID)

1. Receive NTSC signal.

2. Select the "FULL" mode by PIC SIZE button on Remote Control.

3. Call up the adjustment mode display, then select the item WID.

4. Press the VOLUME s or t button to get the picture so that left and right eddes of video signal begin to lack.

5. Press the VOLUME s button to advance the data by 8 steps.

NOTE: Check the horizontal picture position is correct.

SUB-BRIGHTNESS

(BRTC)

1. Receive the air signal or aux Video signal.

2. Enter sports mode on user menu.

3. Enter the service mode, then select “BRTC” register.

4. Adjust the data to set dark area of picture to proper level.

SUB-COLOR

(SCOL)

1. Receive color-bar signal from color-bar generator.

2. Adjust the BRIGHTNESS and CONTRAST to the center (RESET status).

3. Connect oscilloscope to TP501on the MAIN board.

Blue

4. Enter the service mode, then select “SCOL”.

5. Adjust the data value to achieve 1.8V

0-p

of blue bar on scope.

6. Check the picture with off-air signal.

0

Magenta

2

3 (1.8V

0-P

)

– 12 –

HEIGHT

(HIT)

ITEM

VERTICAL LINEARITY

(VLIN)

(FULL mode only)

ADJUSTMENT PROCEDURE

1. Receive NTSC signal.

2. Select the "FULL" mode by PIC SIZE button on Remote Control.

3. Call up the adjustment mode display and select the item HIT.

4. Press the VOLUME s or t button to get the picture so that top and bottom of video signal begin to lack.

5. Press the VOLUME s button to advance the data by 8 steps.

Note: Check the vertical picture position is correct.

Adjust the data of height after vertical linearty.

1. Receive cross-hatch pattern.

2. Call up the adjustment mode display, then select the item VLIN.

3. Press the VOLUME s or t button to obtain the picture of the best linearity.

4. Then readjust the item HIT.

WHITE BALANCE

(RCUT)

(GCUT)

(BCUT)

(RDRV)

(BDRV)

1. Press RESET button on TV or remote hand set.

2. Call up the adjustment mode display, then adjust the data of items RCUT, GCUT and BCUT to “80”.

3. Press TV (ANT)/VIDEO button on TV.

4. Gradually rotate R, G and B SCREEN volume of FOCUS PAC (page 9) clockwise or counterclockwise until the raster appears slightly on the CRT through the each lens, and leave them.

(Look into the lens in order to check the raster.)

5. Press TV (ANT)/VIDEO button on TV again.

6. Exit from service mode.

7. Receive white laster pattern signal, and adjust the contrast to the minimum to make white picture to low light.

8. Adjust the data of items RCUT, GCUT and BCUT for low light area.

9. Adjust the contrast to the maximum to make white picture to high light.

10. Adjust the data of items RDRV and BDRV Controls for proper white-balanced picture in high light area.

11. Check the white balance in both low and high light areas. If necessary, perform again steps from 7 to 9.

– 13 –

CONVERGENCE ADJUSTMENT

Adjust convergence from center to circumference in order.

KEY FUNCTION IN THE CONVERGENCE ADJUSTMENT:

Lord BACK UP DATA:

Up :

Selet Green color:

Left :

Blinking of cursor ON/OFF:

Right:

Adjust mode ON/OFF:

Down:

Vertical stripe ON/OFF

Erase Green line:

Erase Red line:

Erase Blue line:

1 button

2 button

3 button

4 button

5 button

6 button

7 button

8 button

9 button

0 button

100 button

ENT button

Note:

Adjusting procedure in replacing convergence board.

1. User convergence center check. Make sure the best convergence setting is about the center of adjustable range.

2. CENTERING ADJUSTMENT

3. PICTURE POSITION ADJUSTMENT

4. HIT, WID ADJUSTMENT

5. CONVERGENCE ADJUSTMENT

6. Execute TOUCH FOCUS following instructions displayed on the screen after finishing CONVERGENCE ADJUST-

MENT.

7. If TOUCH FOCUS ERROR is displayed after finishing

TOUCH FOCUS, the method of CROSS-HATCH PAT-

TERN after CONVERGENCE adjustment is different from what is exhibited on the right figure, or HARDWARE is out of order.

1. Select the adjustment mode following the steps on page

10.

RCUT

40H

2. Press “7” button to display the built-in cross-hatch pattern and press "9" button to display the vertical stripes.

3. If there is need to load BACKUP DATA, push "1" button, and then push "ENTER" button according to following message. Convergence become adjusted state at factory by this action.

If there is no need, pass this process.

Never to use this function to new convergence board, because BACKUP DATA is not exist.

4. Adjustment around cursor can be done.

The pattern includes three colors (R, G, B).

The cursor should be blinking in Red.

This means that the Red color is adjustable.

5. Press “3” button to select Green color to be adjusted.

6. Press “5” button to stop the blinking of cursor.

7. Press “2 (up)”, “8 (down)”, “4 (left)” or “6 (right)” to obtain the correct cross-hatch pattern as above.

If necessary, the specified color line can be erased from the screen.

100 button ...................... to erase Red line

0 button ...................... to erase Green line

CH RTN button ...................... to erase Blue line

8. Press “5” button to make the cursor blinking.

9. Press “2”, “8”, “4”, “6” buttons to move the cursor to other point to be adjusted.

10. Repeat steps 6 to 9.

11. Repeat steps 5 to 10 to adjust Red and Blue colors.

Converge the selected color line into the Green line.

12. Press “7” button to memorize the adjusted states.

At this time, picture changes for about 1 second.

13. Press the TOUCH FOCUS button when "PLEASE PUSH

TOUCH FOCUS" is displayed on the screen.

14. TOUCH FOCUS CALIBRATION MODE is executed.

15. It retur ns to the normal screen after displaying

"CALIBRATION FINISHED".

– 14 –

Adjusting Dimension of Each Picture Screen

(16:9 screen size:) 50 inches

(1) HD (1080I/NTSC)

50 inches 16:9 Screen Size:horizontal 1106mm :Vertical 622mm

(QH173, 16KB, CHIP1, UFO-*,BANK1) Vspan37.7mm Hspan88.5

345.0

115.0

0 115.0

0

113.1

226.2

301.6

442.5

531.0

22.0

301.6

226.2

113.1

22.0

531.0

442.5

265.5

88.5

0 88.5

Adjusting Dimension of Each Picture Screen

(16:9 screen size:) 65 inches

(1) HD (1080I/NTSC)

65 inches 16:9 Screen Size:horizontal 1442mm :Vertical 810mm

(QH173, 16KB, CHIP1, UFO-*,BANK1) Vspan49.1mm Hspan115.0

265.5

31.0

690.0

575.0

345.0

0

147.3

294.3

392.3

575.0

690.0

31.0

392.3

294.3

147.3

– 15 –

NOTES

In many cases, color misconvergence may be corrected by returning HIT and WID data in main deflection side to initial adjusting values. Following cases will surely require readjustment of convergence.

CRT REPLACEMENT

When CRT is replaced, main deflection readjustment and color matching are required.

Perform following procedures.

1. Replace two CRT’s of blue and red.

2. Perform horizontal adjustment for blue and red yokes on base of green CRT data. Mount yoke and velocity mod. coil alignment, pushing towards CRT without gap.

3. Adjust alignment of blue and red. (Refer Alignment adjustment for details.)

4. Rotating centering magnet, adjust CRT centers of red and blue to CRT center of green.

(Picture position adjustment)

5. Adjust HIT and WID data of main deflection, and decide data at the most precise screen comparing to green data.

6. Adjust convergence of screen picture for color matching. Do not move green one at this time.

7. After convergence adjustment of screen picture finishes, replace green CRT.

For green CRT as well, repeat steps 2 to 5 above on bases of red and blue color matching to adjust convergence.

8. Execute TOUCH FOCUS following instructions displayed on the screen after finishing convergence adjustments of all the colors.

Note: Press button "7" again after "PLEASE PUSH TOUCH FOCUS" has been displayed. Then, TOUCH FOCUS will not be executed, and the current state of convergence will be displayed.

REPLACING CONVERGENCE UNIT

When replacing convergence unit, picture screen require readjustment basically, but the following method allows process be reduced considerably.

1. Replace the memory (Q713) on defective unit with memory on new unit. Mounting the unit on the SET after the above working realizes picture screen before replacement immediately.

2. Mount unit which has old memories, on SET and turn it on. Screen shows whole picture looks like straightly shifted towards vertical or horizontal direction.

3. Adjust again centers of green, red and blue with centering magnets.

4. Check picture screen for slight disparity of color and picture size. If necessary, add some adjustments of main deflection and color matching of convergence.

5. Execute TOUCH FOCUS following instructions displayed on the screen after finishing convergence adjustments of all the colors.

Note: Press button "7" again after "PLEASE PUSH TOUCH FOCUS" has been displayed. Then, TOUCH FOCUS will not be executed, and the current state of convergence will be displayed.

– 16 –

SCREEN AND MIRROR ALIGNMENTS

ASSEMBLING OF FRONT SCREEN MOUNTING OF FRONT SCREEN

INSIDE

0 to 1 mm

K503 FRONT PANEL

K501

LENTICULAR

K502

FRESNAL

<INSIDE>

OUT SIDE

LENS

BLACK STRIPES

FRESNEL

LENTICULAR

FRONT PANEL

<OUTSIDE>

SMOOTH

BLACK STRIPES

SPACER

FRONT PANEL

LENTICULAR

FRESNEL

SMOOTH

BEZEL

SMOOTH

CAUTION : Do not hold the optical system parts (lens and mirror) with bare hand to avoid finger-prints on the surface of those parts.

HOW TO CLEAN LENS AND MIRROR

1. Be sure to remove sand dust with an air brush, etc.

2. When it is stained slightly, breathe upon it and wipe away with the specified cleaning cloth.

For other stains than the above, wipe the stains away with the specified cloth into which a cleaning liquid has been soaked.

Cleaning liquid .................... LENS LUSTER (Manufactured by Edmund Scientific

Co.), etc.

HOW TO CLEAN SCREEN

When cleaning the screen, use a soft cloth so as not to damage the screen.

1. Wipe the screen with a dry cloth to remove moisture on the screen.

Note : Absolutely do not use detergent, water, alcohol, benzine, thinner, etc. for cleaning in order not to wipe away the black print on the surface.

– 17 –

CIRCUIT CHECKS

HIGH VOLTAGE CHECK

CAUTION: There is no HIGH VOLTAGE ADJUSTMENT on this chassis. Checking should be done following the steps below.

1. Connect an accurate high voltage meter to the anode of the picture tube.

2. Turn on the receiver. Set the BRIGHTNESS and CON-

TRAST to minimum (zero beam current).

3. High voltage must be measured below (B) kV.

Refer to table-1 for high voltage (B).

(See SETTING & ADJUSTING DATA on page 19)

4. Vary the BRIGHTNESS to both extremes to be sure the high voltage does not exceed the limit under any conditions.

CAUTION:

When the following parts fail, check the High Voltage after replacing.

Location

No.

T461

C407

C408

C441

C432

C433

Name

Flyback

Capacitor

Capacitor

Capacitor

Capacitor

Capacitor

Descriptions

50", 65"

TFB3092AD

4700pF,

±3%

8200pF,

±5%

4700pF,

±3%

8200pF,

±5%

1200pF,

±3%

FS CIRCUIT CHECK

The Fail Safe (FS) circuit check is indispensable for the final check in servicing. Checking should be done following the steps below.

1. Turn the receiver on.

2. Temporarily short TP- (R) and TP- (X) on the DEF/POWER

Board with a jumper wire.

Raster and sound will disappear.

3. The receiver must remain in this state even after removing the jumper wire. This is the evidence that the FS circuit is functioning properly.

4. To obtain a picture again, temporarily turn the receiver off and allow the FS circuit more than 5 seconds to reset. Then turn the receiver on to produce a normal picture.

Troubleshooting Guide for Fail Safe Circuit

Check that the set returns to normal operation when pin 12 of Z801 is grounded with jumper wire.

YES NO

Check the voltage across

Capacitor C419 is approximately ( C) volts.

Refer to table –3 for fall safe voltage (

C)

.

YES

Faulty power circuit or horizontal circuit.

(See SETTING & ADJUSTING

DATA on page 19)

ANODE VOLTAGE MEASURING METHOD

CAUTION: Take extra precaution when measuring this high voltage. High voltages are also present in surrounding circuit boards (CRT DRIVE assembly, DEFLECTION assembly, and POWER

SUPPLY assembly).

1. Disconnect the FBT anode cable as outlined below. Measure high voltage at the point where the cable enters the

FBT.

2. Holding the rubber cover firmly, turn it counterclockwise and check that the lock has been disengaged. (See Fig. b on page 9.)

3. Determine the extent of the rubber cover before disconnecting the cable.

4. Pull straight up the anode cable to disconnect.

5. When reconnecting the cable, proceed in the reverse order.

After reconnecting, tug on the cable to check that it is secure.

Defective Fail Safe Circuit

NO

– 18 –