Sony KV-TG21M70, KV-TG21M90 Service Manual

REVISION HISTORY

BG3R

CHASSIS

MODEL

KV-TG21M70 KV-TG21M90/N

NO. SUFFIX DATE SUPPL. / CORR DESCRIPTION

1 -01 2001/10 -- 1st. Issue

PA RT NO. : 9-872-273-01

SERVICE MANUAL

BG2T

CHASSIS

MODEL COMMANDER DEST. CHASSIS NO.

KV-TG21M70 RM-952 India SCC-U74B-A KV-TG21M90/N RM-952 Hong Kong SCC-U64E-A

(CHAMPAGNE GOLD)

MODEL COMMANDER DEST. CHASSIS NO.

JUMP

SOUND

PROGRÁ

MODE

FAVORITE

TRINITRON

COLOR TV

KV-TG21M70/TG21M90/N

RM-952

Power requirements 110-240 V AC, 50/60 Hz KV-TG21M70

Power consumption (W) Indicated on the rear of the TV

Television system B/G, I, D/K, M

Color system PAL, PAL 60, NTSC3.58, NTSC4.43 SECAM

Stereo/Bilingual system Nicam Stereo/Bilingual B/G, I, D/K; A2 Stereo/Bilingual B/G KV-TG21M90/N

Channel coverage

B/G CATV: S01 to S03, S1 to S41

I UHF: B21 to B68 / CATV: S01 to S03, S1 to S41

D/K VHF: C1 to C12, R1 to R12 / UHF: C13 to C57, R21 to R60

M VHF: A2 to A13

˘ (Antenna) 75-ohm external terminal

Audio output (Speaker) 3W + 3W

Number of terminal

D Video Input: 2* Output: 1 Phono jacks; 1 VP-P, 75 ohms * One input line available

≥ Audio Input: 2* Output: 1 Phono jacks; 500 mVrms * One input line available 2 (Headphone) Output: 1 Stereo minijack KV-TG21M90/N

(Earphone) Output: 1 Monaural minijack KV-TG21M70

Picture tube 21 in.

Tube size (cm) 54 Measured diagonally

Screen size (cm) 51 Measured diagonally

Dimension (w/h/d, mm) 497 x 458 x 487

Mass (kg) 25

SPECIFICATIONS

Note

220-240 V AC, 50/60 Hz KV-TG21M90/N

VHF: E2 to E12 / UHF: E21 to E69 /

CATV: S01 to S03, S1 to S41, Z1 to Z39

UHF: A14 to A79 CATV: A-8 to A-2, A to W+4, W+6 to W+84

CAUTION

SHORT CIRCUIT THE ANODE OF THE PICTURE TUBE AND THE ANODE CAP TO THE METAL CHASSIS, CRT SHIELD, OR CARBON PAINTED ON THE CRT, AFTER REMOVING THE ANODE.

Design and specifications are subject to change without notice.

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY SHADING AND MARK ! ON THE SCHEMATIC DIAGRAMS, EXPLODED VIEWS AND IN THE PARTS LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY.

– 2 –

KV-TG21M70/TG21M90/N

RM-952

Section Title Page

SELF DIAGNOSTIC FUNCTION ................................... 4

1. GENERAL ................................................................. 7

2. DISASSEMBLY

2-1. Rear Cover Removal ............................................... 11

2-2. Speaker Removal .................................................... 11

2-3. Chassis Assy Removal ............................................ 11

2-4. Service Position ...................................................... 11

2-5. Terminal Bracket Removal ..................................... 11

2-6. Replacement of Parts .............................................. 12

2-6-1. Replacement of Light Guide ........................ 12

2-6-2. Replacement of Power Button ..................... 12

2-7. Picture Tube Removal ............................................. 12

3. SET-UP ADJUSTMENTS

3-1. Beam Landing ......................................................... 14

3-2. Convergence ............................................................ 15

3-3. Focus Adjustment.................................................... 17 3-4. G2 (SCREEN) and White Balance Adjustments ... 17

4. CIRCUIT ADJUSTMENTS

4-1. Adjustment With Commander ................................ 18

4-2. Adjustment Method ................................................ 18

4-3. Picture Quality Adjustment .................................... 24

4-4. Deflection Adjustment ............................................ 24 4-5. A Board Adjustment After IC003 (MEMORY)

Replacement ............................................................ 24

4-6. Picture Distortion Adjustment ................................ 25

Section Title Page

5. DIAGRAMS

5-1. Block Diagram ........................................................ 27

5-2. Circuit Boards Location .......................................... 29

5-3. Schematic Diagram ................................................. 30

(1) A Board Schematic Diagram ............................ 31

(2) A3 Board Schematic Diagram .......................... 33

(3) CV Board Schematic Diagram ......................... 35

(4) F Board Schematic Diagram ............................. 36

5-4. Voltage Measurement ............................................. 39

5-5. Waveforms .............................................................. 42

5-6. Printed Wiring Boards and Parts Location ............. 43

5-7. Semiconductors ....................................................... 47

6. EXPLODED VIEWS

6-1. Picture Tube and Chassis ........................................ 49

7. ELECTRICAL PARTS LIST.................................... 50

– 3 –

KV-TG21M70/TG21M90/N

RM-952

SELF DIAGNOSTIC FUNCTION

The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY/TIMER lamp will automatically begin to flash. The number of times the lamp flashes translates to a probable source of the problem. A definition of the STANDBY/ TIMER lamp flash indicators is listed in the instruction manual for the user’s knowledge and reference. If an error symptom cannot be reproduced, the remote commander can be used to review the failure occurrence data stored in memory to reveal past problems and how often these problems occur.

1. DIAGNOSTIC TEST INDICATORS

When an errors occurs, the STANDBY/TIMER lamp will flash a set number of times to indicate the possible cause of the problem. If there is more than one error, the lamp will identify the first of the problem areas.

Result for all of the following diagnostic items are displayed on screen. No error has occured if the screen displays a “0”.

Diagnostic

Item

Description

• Power does not turn on

• +B overcurrent (OCP)

• Horizontal deflection overdrive

• White balance failure (no PICTURE)

• Vertical deflection stopped

• Micro reset

No. of times

STANDBY/TIMER

lamp flashes

Does not light

2 times

4 times

—

Self-diagnostic

display/Diagnostic

result

—

002:000 or

002:001~255

004:000 or

004:001~225

101:00 or

101:001~225

Probable

Cause

Location

• Power cord is not plugged in.

• Fuse is burned out F4601 (F)

• H.OUT Q801 is shorted. (A board)

• -13V is not supplied. (CV Board)

• IC551 faulty (A board)

• Discharge CRT (CV Board)

• Static discharge

• External noise

Detected

Symptoms

• Power does not come on.

• No power is supplied to the TV.

• AC power supply is faulty.

• Power does not come on.

• Load on power line is shorted.

• Has entered standby state after horizontal raster.

• Power line is shorted or power supply is stopped.

• Vertical deflection pulse is stopped

• Power is shut down shortly, after this return back to normal.

• Detect Micro latch up.

Note 1: If a + B overcurrent is detected, stoppage of the vertical deflection is detected simultaneously.

The symptom that is diagnosed first by the microcontroller is displayed on the screen.

Note 2: Refer to screen (G2) Adjustment in section 3-4 of this manual.

– 4 –

2. DISPLAY OF STANDBY/TIMER LIGHT FLASH COUNT

2 times

KV-TG21M70/TG21M90/N

RM-952

Diagnostic Item Flash Count*

+B overcurrent/overvoltage 2 times

4 times

Lamp ON 0.3 sec.

Lamp OFF 0.3 sec.

Lamp OFF 3 sec.

Vertical deflection stopped 4 times

* One flash count is not used for self-diagnostic.

STANDBY/SLEEP lamp

3. STOPPING THE STANDBY/TIMER FLASH

Turn off the power switch on the TV main unit or unplug the power cord from the outlet to stop the STANDBY/TIMER lamp from flashing.

4. SELF-DIAGNOSTIC SCREEN DISPLAY

For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confirmed, it is possible to bring up past occurances of failure for confirmation on the screen:

[To Bring Up Screen Test]

In standby mode, press buttons on the remote commander sequentially in rapid succession as shown below:

[Screendisplay] / channel [5] / Sound volume [-] / Power ON

Note that this differs from entering the service mode (mode volume [+]).

Self-Diagnosis screen display

SELF DIAGNOSTIC

002 : 000 004 : 000

101 : 000

Numeral "0" means that no fault has been detected.

– 5 –

KV-TG21M70/TG21M90/N

RM-952

5. HANDLING OF SELF-DIAGNOSTIC SCREEN DISPLAY

Since the diagnostic results displayed on the screen are not automatically cleared, always check the self-diagnostic screen during repairs. When you have completed the repairs, clear the result display to “0”.

Unless the result display is cleared to “0”, the self-diagnostic function will not be able to detect subsequent faults after completion of the repairs.

[Clearing the result display]

To clear the result display to “0”, press buttons on the remote commander sequentially as shown below when the diagnostic screen is being displayed.

Channel [8] / 0

[Quitting Self-diagnostic screen]

To quit the entire self-diagnostic screen, turn off the power switch on the remote commander or the main unit.

6. SELF-DIAGNOSTIC CIRCUIT

FROM [+B] Q500

IC301

Y/CHROMA JUNGLE

MP/

PROTECT

SDA

[V] D553

IC001

SYSTEM

IO-8DAT B-DAT

O-LED

IO-SDAT

IC003

MEMORY

[+BovercurrentªOCPº] Occurs when an overcurrent on the +B(135) line is detected by Q500. If Q500 go to

ON and the voltage to pin 50 of IC301 more than 3.5V when V.SYNC is more than seven verticals in a period, the unit will automatically turn off.

[Verticaldeflectionstopped] Occurs when an absence of the vertical deflection pulse is detected by Pin 17 and

IC001 shut down the power supply.

[Whitebalancefailure] If the RGB levels* do not balance or become low level within 5 seconds, this error

will be detected by IC301. TV will stay on, but there will be no picture.

* (Refers to the RGB levels of the AKB detection Ref pulse that detects IK.)

– 6 –

KV-TG21M70/TG21M90/N

RM-952

A Getting Started

Step 1

SELECT

PROGR

SELECT

Insert the batteries (supplied) into the remote.

Note

• Do not use old batteries nor use different types of batteries together.

Step 2

Connect the antenna cable (not supplied) to 8 (antenna input) at the rear of the TV.

Tip

• You can also connect your TV to other optional components. (See E)

Step 3

Plug in the power cord, then press ! on the TV to turn it on.

Step 4

Press SELECT and PROGR + on the TV at the same time for one to two seconds to preset the channels automatically. (See J)

Tip

• To stop the automatic channel presetting, press SELECT.

Step 5

Press SELECT on the remote until “LANGUAGE/ : ENGLISH” appears on the screen, then press + or – to change the on-screen display language.

(KV-TG21M70)

WARNING

• Dangerously high voltages are present inside the TV.

• TV operating voltage: 110 – 240 V AC. (KV-TG21M70)

• Do not plug in the power cord until you have completed making all other connections;

otherwise a minimum leakage current might flow through the antenna and other terminals to ground.

• To avoid battery leakage and damage to the remote, remove the batteries from the remote if you are not going to use it for several days. If any liquid that leaks from the batteries touches you, immediately wash it away with water.

For your own safety, do not touch any part of the TV, the power cord and the antenna cable during lightning storms.

To prevent fire or shock hazard, do not expose the TV to rain or moisture.

Do not block the ventilation openings of the TV. Do not install the TV in a confined space, such as a bookcase or built-in cabinet.

Do not open the cabinet and the rear cover of the TV as high voltages and other hazards are present inside the TV. Refer servicing and disposal of the TV to qualified personnel.

220 – 240 V AC. (KV-TG21M90/N)

For children’s safety, do not leave children alone with the TV. Do not allow children to climb onto it.

Do not operate the TV if any liquid or solid object falls into it. Have it checked immediately by qualified personnel only.

Clean the TV with a dry and soft cloth. Do not use benzine, thinner, or any other chemicals to clean the TV. Do not scratch the picture tube.

Your TV is recommended for home use only. Do not use the TV in any vehicle or where it may be subject to excessive dust, heat, moisture or vibrations.

A Getting Started

GENERAL

SECTION 1

SELECT

PROGR

SELECT

(KV-TG21M90/N)

WARNING (continued)

Step 1

Insert the batteries (supplied) into the remote.

Note

• Do not use old batteries nor use different types of batteries together.

Do not place any objects on the TV.

Step 2

Connect the antenna cable (not supplied) to 8 at the rear of the TV.

Tip

• You can also connect your TV to other optional components. (See E)

Step 3

Plug in the power cord, then press ! on the TV to turn it on.

Install the TV on a stable TV stand and floor which can support the TV set weight. Ensure that the TV stand surface is flat and its area is larger than the bottom area of the TV.

Securing the TV

To prevent the TV from falling, use the supplied screws, clamps and band to secure the TV

20 mm

screws clamps band

3.8 mm

Step 4

Press SELECT and PROGR + on the TV at the same time for one to two seconds to preset the channels automatically. (See J)

Tip

• To stop the automatic channel presetting, press SELECT twice.

Step 5

Press SELECT on the remote until “LANGUAGE/ : ENGLISH” appears on the screen, then press + or – to change the on-sceen display language.

Do not plug in too many appliances to the same power socket. Do not damage the power cord.

Pull the power cord out by the plug. Do not pull the power cord itself. Even if your TV is turned off, it is still connected to the AC power source (mains) as long as the power cord is plugged in. Unplug the TV before moving it or if you are not going to use it for several days.

Screw the band to the TV stand and to the provided hole at the rear of your TV.

(1) Put a cord or chain through the

clamps.

(2) Screw one clamp to a wall or pillar

and the other clamp to the provided hole at the rear of your TV.

The operating instruction mentioned here are partial abstracts

from the Operating Instruction Manual. The page numbers of

the Operating Instruction Manual remain as in the manual.

– 7 –

Note

• Use only the supplied screws. Use of other screws may damage the TV.

KV-TG21M70/TG21M90/N

RM-952

TV front and rear panels

TV front panel

(MONO)

★

Button Function

! Turn off completely or turn on the TV.

2 3

1 Standby indicator.

3 3 3 4

PROGR +/– Select program number.

2 +/– * Adjust volume.

t Select TV or video input.

SELECT Select the desired item.

i Headphone terminal. (KV-TG21M90/N)

8 9, qa

t Video input terminal.

8 Antenna terminal.

T Monitor output terminal.

* You can also use the 2 +/– buttons on the TV to work as the +/– buttons on the remote.

★

The R (audio input) jacks are only available for KV-TG21 only.

TV rear panel

L(MONO)R

★

SELECT

Remote control sensor.

Stereo/bilingual indicator. (KV-TG21M90 only)

Bilingual indicator. (KV-PG14M72 only)

Wake Up indicator.

Earphone terminal. (KV-TG21M70)

PROGR

Troubleshooting

If you find any problem while viewing your TV, please check the following guide. If any problem persists, contact your Sony dealer.

Symptom Solutions

Snowy picture, noisy sound

Good picture, noisy sound

No picture,no sound

Good picture, no sound

Dotted lines or stripes

Double images or “ghosts”

No color

Abnormal color patches

The 1 (standby)

indicator on your TV flashes red several times after every three seconds.

TV cabinet creaks.

A "boom" sound is heard when the TV is turned on.

• Check the antenna cable and connection on the TV, VCR and on the wall.

• Preset the channel manually again. (See J)

• Check the antenna setup. Contact a Sony dealer for advice.

• Select the appropriate TV system. (See J)

• Press A/B until the sound is optimal. (KV-TG21M90 only)

• Check the power cord, antenna and the VCR connections.

• Press ?/1 (power) or ! (main power) to turn on the TV.

• Press 2 + to increase the volume level.

• Press % to cancel the muting.

• Do not use a hair dryer or other equipment near the TV.

• Check the antenna setup. Contact a Sony dealer for advice.

• Use the fine tuning ("FINE") function. (See J)

• Turn off or disconnect the booster if it is in use.

• Check the antenna setup. Contact a Sony dealer for advice.

• Select the appropriate color system. (See J)

• Adjust the color level. (See K)

• Check the antenna setup. Contact a Sony dealer for advice.

• Keep external speakers or other electrical equipment away from the TV.

Press ! (main power) to turn off the TV for about 15 minutes, then turn it on again to demagnetize the TV.

• Count the number of times the 1 (standby) indicator flashes. Press !

(main power) to turn off your TV. Contact your nearest Sony service center.

• Changes in room temperature sometimes make the TV cabinet expand or contract, making a noise. This does not indicate a malfunction.

• The TV's demagnetizing function is working. This does not indicate a malfunction.

Connecting optional components

Connecting to the video input terminal ( t )

TV front panel

TV rear panel

(MONO)

L(MONO)R

★

Audio/Video cable

(not supplied)

Antenna cable

(not supplied)

Audio/Video cable

(not supplied)

Camcorder

Video game

equipment

VCR

★

Note

• Do not connect video equipment to t (video input) at the front and the rear of your TV at

the same time; otherwise the picture will not be displayed properly on the screen.

Connecting to the monitor output terminal (T)

TV rear panel

L(MONO)R

Audio/Video cable

(not supplied)

Audio system

Remote control

0 qa qs

SOUND MODE

JUMP

PROGR

qj qk

FAVORITE

Button Function

?/1 Turn off temporarily or

JUMP Jump to previous

PROGR +/– Select program number.

2 +/–

SELECT Select the desired item.

PIC MODE Select picture mode.

+/– Adjust items.

0 – 9, ÷ Input numbers.

Timer operations

Sound mode operations (KV-TG21M90 only)

SOUND MODE Select sound mode.

Stereo/bilingual operations (KV-TG21M90 only)

A/B Select stereo/bilingual

Teletext operations

x (red, green,

yellow, blue)

0 qs qd qh qj qk

FAVORITE

turn on the TV.

Display the TV program.

program number.

Adjust volume.

Display on-screen information.

Mute the sound.

Select TV or video input.

Set TV to turn on automatically.

Set TV to turn off automatically.

mode.

Not function for your TV.

See

–

★

The R (audio input) jacks are only available for KV-TG21 only.

VCR

– 8 –

KV-TG21M70/TG21M90/N

RM-952

Setting the timers

You can turn on and off your TV by using the and buttons respectively.

Setting the Wake Up timer

\/1

SOUND

MODE

FAVORITE

Press until the desired period of time appears

on the screen.

WAKE UP TIMER:0H10M

(After 10 minutes)

JUMP

PROGR

WAKE UP TIMER:OFF (No Wake Up timer) (After 12 hours)

The Wake Up timer starts immediately after you have set it.

Select the program number or video input you

want to wake up to.

Press \/1, or set the Sleep timer if you want the

TV to turn off automatically.

indicator on the TV lights up orange when

The the TV goes into standby mode.

WAKE UP TIMER:12H00M

Setting the Sleep timer

Press until the desired period of time appears on the screen.

SLEEP TIMER:30M SLEEP TIMER:60M (After 30 minutes)

SLEEP TIMER:OFF SLEEP TIMER:90M (No Sleep timer)

The Sleep timer starts immediately after you have set it.

Notes

• You can also cancel the Wake Up and Sleep timers by turning off the TV’s main power.

• If no buttons or controls are pressed for more than two hours after the TV is turned on using

the Wake Up timer, the TV automatically goes into standby mode.

(After 60 minutes)

(After 90 minutes)

Presetting channels (continued)

To change the TV system setting

If the picture or sound is abnormal when receiving programs through the 8 (antenna) terminal

(1) Press SELECT until “TV SYS” appears on the screen.

(2) Press + or – to select the appropriate TV system until the picture or sound quality

is optimal.

B/G I D/K M

To change the color system setting

If the color is abnormal when receiving programs through the 8 (antenna) terminal or the t (video input) terminal

(1) Press SELECT until “COLOR SYS” appears on the screen.

(2) Press + or – to select the appropriate color system until the color is optimal.

AUTO PAL SECAM NTSC3.58 NTSC4.43

To skip program numbers

(1) Press PROGR +/– or the number buttons until the unused or unwanted program

number appears on the screen.

(2) Press SELECT until “MANUAL PROGRAM” appears on the screen.

(3) Press + or – once to enter the “MANUAL PROGRAM” mode.

(4) Press PIC MODE to skip the unused or unwanted program number.

(5) Press SELECT to exit the “MANUAL PROGRAM” mode.

Note

• To restore the skipped program number again, preset the channel automatically or manually.

To use the fine tuning function

The fine tuning (FINE) function may help to reduce the following problems: double images and lines moving across the TV screen.

You can use the fine tuning function as below:

(1) Select the program number you want to adjust.

(2) Press SELECT until “MANUAL PROGRAM” appears on the screen.

(3) Press + or – once to enter the “MANUAL PROGRAM” mode.

(4) Press

to display “FINE” on the screen.

(5) Press + or – continuously until the above problems are minimized.

The + or – icon on the screen flashes while tuning.

(6) Press SELECT to exit the “MANUAL PROGRAM” mode.

Presetting channels

You can automatically preset up to 100 TV channels in numerical sequence from program number 1, or manually preset desired channels and channels that cannot be preset automatically.

Presetting channels automatically from a specified program number

Press SELECT until “AUTO PROGRAM” appears

Number buttons

+ or –

PIC MODE

SELECT

PROGR +/–

SOUND

MODE

FAVORITE

on the screen.

Press + or – once to enter the “AUTO

JUMP

PROGRAM” mode.

PROGR

The on-screen display will start flashing.

Press PROGR +/– or the number buttons until

the desired program number appears on the screen.

Press + or – to start presetting channels

automatically.

Presetting channels manually

Press SELECT until “MANUAL PROGRAM”

appears on the screen.

Press + or – once to enter the “MANUAL

PROGRAM” mode.

Press PROGR +/– or the number buttons until

the desired program number appears on the screen.

Press + or – until the desired channel picture

appears on the screen.

To preset other channels manually, repeat steps

3 to 4.

Customizing the picture

You can customize the picture by selecting the picture mode or by adjusting its settings.

(KV-TG21M70)

Selecting the picture mode

Press PIC MODE to select the desired picture mode.

Select To

“DYNAMIC” view high contrast pictures.

“STANDARD” view normal contrast pictures.

JUMP

SOUND

MODE

SELECT

+ or –

PIC MODE

Notes

•“HUE” can be adjusted for the NTSC color system only.

• Reducing “SHARP” can also reduce picture noise.

FAVORITE

“SOFT” view mild pictures.

PROGR

Adjusting the picture setting

1Press SELECT until the desired setting appears.

Each time you press SELECT, the setting item will change as follows:

PICTURE COLOR BRIGHT

HUE

SHARP

Press + or – to adjust the item.

To adjust other items, repeat steps 1 to 2.

– 9 –

KV-TG21M70/TG21M90/N

NICAM MAIN

(Main sound)

NICAM SUB (Sub sound)

MONO

(Regular sound)

NICAM MAIN

(Main sound)

MONO

(Regular sound)

RM-952

Customizing the picture and sound

(KV-TG21M90/N) You can customize the picture and sound by selecting the picture and sound modes or by adjusting its settings.

JUMP

SOUND

PROGR

MODE

SOUND

MODE

SELECT

+ or –

FAVORITE

PIC MODE

Adjusting the picture and sound settings

Press SELECT until the desired setting appears.

Each time you press SELECT, the setting item will change as follows:

PICTURE COLOR BRIGHT HUE

BALANCE TREBLE BASS

Press + or – to adjust the item.

To adjust other items, repeat steps 1 to 2.

Notes

•“BASS”, “TREBLE” and “BALANCE” can be adjusted for KV-TG21M90 only.

•“HUE” can be adjusted for the NTSC color system only.

• Reducing “SHARP” can also reduce picture noise.

Selecting the picture mode

Press PIC MODE to select the desired picture mode.

Select To

“DYNAMIC” view high contrast pictures.

“STANDARD” view normal contrast pictures.

“SOFT” view mild pictures.

Selecting the sound mode

B KV-TG21M90 only

Press SOUND MODE to select the desired sound mode.

Select To

“9 DYNAMIC” listen to dynamic and clear

“9 DRAMA” listen to sound that emphasizes

“9 SOFT” listen to soft sound.

SHARP

sound that emphasizes the low and high sound.

vocals and background music.

Enjoying stereo or bilingual programs

You can enjoy stereo sound or bilingual programs of NICAM and A2 stereo systems by using the A/B button.

(KV-TG21M90/N)

When receiving a NICAM program

Broadcasting On-screen display (Selected sound)

NICAM

stereo

(KV-TG21M90 only)

JUMP

SOUND

MODE

NICAM

PROGR

bilingual

NICAM

(Stereo sound)

MONO

(Regular sound)

A/B

FAVORITE

NICAM monaural

When receiving an A2 program

Broadcasting On-screen display (Selected sound)

A2 stereo

A2 bilingual

Notes

• If the sound is distorted when receiving a monaural program through the 8 (antenna)

terminal, press A/B repeatedly until “MONO” appears on the screen. To cancel the monaural sound setting, press A/B again until “AUTO” appears on the screen.

KV-TG21M90 only

• If the stereo sound is noisy when receiving a stereo program, select “MONO”. The sound becomes monaural, but the noise is reduced.

• Before receiving a NICAM stereo program in China, please check the NICAM broadcast condition in your area. When receiving a NICAM stereo program, the receiving conditions might vary depending on area. In addition, different strength of the NICAM broadcast signal might affect the receiving quality.

MONO

(Regular sound)

MAIN

(Main sound)

STEREO

(Stereo sound)

(Sub sound)

SUB

Adjusting the picture position

KV-TG21M90/N only

If the picture is slanting, you can adjust the picture position using the “PIC ROTATION” function until it is optimal.

Slanting Optimal

Press SELECT repeatedly until “PIC ROTATION”

+ or –

FAVORITE

SELECT

Note

• To reduce the slanting picture, keep external speakers or other electrical equipment away from the TV.

appears on the screen.

Press + or – to adjust the picture position.

The adjusting.

Good morning!

or icon on the screen flashes while

– 10 –

1 Eight screws

(+BVTP 4 × 16)

1 Rear Cover

2-1. REAR COVER REMOVAL

1 Four screws

(BVTP 3 × 12)

CRT SUPPORT BLOCK

1 Four screws

(BVTP 3 × 12)

Push claw

1 One screw

(+BVTP 4 × 16)

2 Terminal Bracket

– 11 –

SECTION 2

DISASSEMBLY

2-2. SPEAKER REMOVAL

2-3. CHASSIS ASSY REMOVAL

2-4. SERVICE POSITION

Caution:

standing position.

Note:

placing the chassis into Service Position.

Do not take out CRT support block while TV set in

Undress necessary wires that creates tension while

2-5. TERMINAL BRACKET REMOVAL

KV-TG21M70/TG21M90/N

RM-952

KV-TG21M70/TG21M90/N

One screw (+BVTP 3 × 12)

1 Push to direction of arrow

and remove

9 Demagnetic coil

!™ Two screws

(Tapping 5+ Crown Washer)

Tension spring

4 Chassis assy

5 Deflection

yoke

3 CV board

2 Anode

cap

!¡ Coating earth assy

!£ Picture tube

1 Cushion

!™

Two screws (Tapping 5 + Crown Washer)

Holder DGC

6 PWB Bracket

7 CRT Support Block

Screw Location

Beznet Hook

!º

2-6. REPLACEMENT OF PARTS

For replacements of light guide,unscrew them, exchange with new parts and fix them with screws respectively.

2-7. PICTURE TUBE REMOVAL

Note:

• Please make sure the TV set is not in standing position before removing necessary CRT support located on bottom right and left.

RM-952

2-6-1. Replacement of Light Guide

2-6-2. Replacement of Power Button

– 12 –

• REMOVAL OF ANODE-CAP

Anode button

NOTE : After removing the anode, short circuit the anode of the picture tube and

the anode cap to the metal chassis, CRT shield or carbon paint on the CRT.

• REMOVING PROCEDURES

1 Turn up one side of the rubber cap in the direction indicated by the arrow a.

– 13 –

2 Using a thumb pull up the rubber cap firmly in the direction indicated by the arrow b.

3 When one side of the rubber cap is separated from the anode button, the anode-cap

can be removed by turning up the rubber cap and pulling it up in the direction of the arrow c.

• HOW TO HANDLE AN ANODE-CAP

1 Do not damage the surface of anode-caps with sharp shaped objects. 2 Do not press the rubber too hard so as not to damage the inside of anode-cap.

A metal fitting called the shatter-hook terminal is built into the rubber.

3 Do not turn the foot of rubber over too hard.

The shatter-hook terminal will stick out or damage the rubber.

KV-TG21M70/TG21M90/N

RM-952

KV-TG21M70/TG21M90/N

RM-952

SECTION 3

SET-UP ADJUSTMENTS

The following adjustments should be made when a complete

realignment is required or a new picture tube is installed.

These adjustments should be performed with rated power

supply voltage unless otherwise noted.

Controls and switches should be set as follows unless otherwise

noted:

PICTURE control ........................................................... normal

BRIGHTNESS control................................................... normal

................................................................................................................................................................................................................................

Preparation :

In order to reduce the influence of geomagnetism on the set's picture tube, face it east or west. Switch on the set's power and degauss with the degausser.

Perform the adjustments in the following order :

1. Beam Landing

2. Convergence

3. Focus

4. White Balance

Note : Test Equipment Required.

1. Pattern Generator

2. Degausser

3. Oscilloscope

Purity control

3-1. BEAM LANDING

1. Input a white signal with the pattern generator. Contrast Brightness

2. Set the pattern generator raster signal to a green raster.

3. Move the deflection yoke to the rear and adjust with the purity control so that the green is at the center and the blue and the red take up equally sized areas on each side. (See Figures 3-1 through 3-4.)

4. Move the deflection yoke forward and adjust so that the entire screen is green. (See Figure 3-1.)

5. Switch the raster signal to blue, then to red and verify the condition.

6. When the position of the deflection yoke has been decided, fasten the deflection yoke with the screws and DY spacers.

7. If the beam does not land correctly in all the corners, use a magnet to adjust it. (See Figure 3-4.)

}

normal

Fig. 3-2

Blue

Red

Green

Fig. 3-3

Fig. 3-1

Purity control corrects this area.

Deflection yoke positioning corrects these areas.

Fig. 3-4

Disk magnets or rotatable disk magnets correct these areas (a-d).

– 14 –

KV-TG21M70/TG21M90/N

b b

RM-952

3-2. CONVERGENCE

Preparation :

• Before starting this adjustment, adjust the focus, horizontal size and vertical size.

• Receive dot/hatch signal.

• Pic mode: Soft.

(1) Horizontal and Vertical Static Convergence

Center dot

R G B

H. STAT VR

V. STAT

Magnet

RV702

H. STAT

• Operation of V. Stat magnet If the V. Stat magnet is moved in the "a" and "b" arrows, the red, green and blue dots move as shown below.

RGGBB

CV Board

1. (Moving vertically), adjust the V.STAT magnet so that the red, green and blue dots are on top of each other at the center of the screen.

2. (Moving horizontally), adjust the H.STAT VR control so that the red, green and blue dots are on top of each other at the center of the screen.

3. If the H.STAT variable resistor cannot bring the red, green and blue dots together at the center of the screen, adjust the horizontal convergence with the H.STAT variable resistor and the V.STAT magnet in the manner given below. (In this case, the H.STAT variable resistor and the V.STAT magnet influence each other, so be sure to perform adjustments while tracking.)

BMCPurity

BMC (Hexapole)

Purity

4 BMC (Hexapole) Magnet.

If the red, green and blue dots are not balanced or aligned, then use the BMC magnet to adjust in the manner described below.

RG B R G B R GB

DY pocket

V.STAT

– 15 –

KV-TG21M70/TG21M90/N

RM-952

(2) Dynamic Convergence Adjustment

Preparation:

Before starting this adjustment, adjust the horizontal static

convergence and the vertical static convergence

TLH TLV

YCH XCV

TLH Insert TLH Correction Plate to DY Pocket (Left or

Right)

YCH Rotate YCH VOL on DY

TLV Rotate TLV VOL ON DY XCV Rotate XCV Adj core on DY

ON DY:

YCH

TLV

DY pocket

XCV

– 16 –

KV-TG21M70/TG21M90/N

RM-952

(3) Screen-corner Convergence

a-d : screen-corner misconvergence

Fix a Permalloy assy corresponding to the misconverged areas

a to d : Permalloy assembly

3-3. FOCUS ADJUSTMENT

FOCUS adjustment should be completed before W/B adjustment.

1. Receive digital monoscope pattern.

2. Set "Picture Mode" to "DYNAMIC".

3. Adjust focus VR so that the center of screen becomes just focus.

4. Change the receiving signal to white pattern and blue back.

5. Confirm magenta ring is not noticeable. Incase magenta is very obvious, adjust focus VR to take balance of magenta ring and focus.

3-4. G2 (SCREEN) AND WHITE BALANCE

ADJUSTMENTS

1. G2 (SCREEN) ADJUSTMENT

1) Set the PICTURE to normal.

2) Put to VIDEO input mode without signals.

3) Connect R, G and B of the CV board cathode to the oscilloscope.

4) Adjust BRIGHTNESS to obtain the cathode voltage to the value below.

5) Adjust G2 (screen) on the FBT until picture shows the point before cut off.

Cathode setting voltage:

175 V ± 2 (VDC)

0 V

2.a). WHITE BALANCE ADJUSTMENT

1) Set to Service Mode (Refer Section 4-1: ADJUSTMENTS WITH COMMANDER).

2) Input white raster signal.

3) Set ABL (49) and VP2 (IF) service mode to 00.

4) Set Picture to DYNAMIC.

5) Select RDR (0B) with [1] and [4], and set the level to 25 with [3] and [6] for best white balance.

6) Select GDR (0C) and BDR (0D) with [1] and [4], and adjust the level with [3] and [6] for the best white balance.

7) Write into the memory by pressing [MUTING] then [0].

8) Set back ABL (49) and VP2 (IF) service mode to original data.

2.b).SUB BRIGHT ADJUSTMENT

1) Set to service mode.

2) Set ABL (49) and VP2 (IF) service mode to 00

3) Input a staircase signal of black to white from the pattern generator.

4) BRIGHTNESS ....50%.

PICTURE ............MINIMUM

5) Select OE (SBR) with [1] and [4], and adjust OE (SBR) level with [3] and [6] so that the second stripe from the right is dimly lit.

6) Write into the memory by pressing [MUTING] then [0].

7) Set back ABL (49) and VP2 (IF) service mode to original data.

FOCUS

SCREEN

FLYBACK TRANSFORMER (T503)

White

second from the right

Black

– 17 –

+ 39 hidden pages

Sony KV-TG21M70, KV-TG21M90 Service Manual

REVISION HISTORY

SPECIFICATIONS

TABLE OF CONTENTS

SELF DIAGNOSTIC FUNCTION

GENERAL

DISASSEMBLY

SET-UP ADJUSTMENTS