SONY BA6 Diagram

SERVICE MANUAL

MODEL COMMANDER DEST CHASSIS NO.

KV-20M42 RM-Y156 US SCC-S27A-A KV-20M42 RM-Y156 CND SCC-S28B-A KV-20S42 RM-Y155 US SCC-S27B-A KV-20S42 RM-Y155 CND SCC-S28C-A KV-20S43 RM-Y156W US SCC-S27C-A KV-20S43 RM-Y156W CND SCC-S28D-A KV-21MB42C RM-Y156 E SCC-S25E-A KV-21MB42M RM-Y156 MX SCC-S26A-A KV-21MB42P RM-Y156 E SCC-S25A-A KV-21ME42 RM-Y156 E SCC-S25B-A KV-21ME42C RM-Y156 E SCC-S25F-A KV-21SB42C RM-Y155 E SCC-S25G-A

BA-4D CHASSIS

KV-21SB42M RM-Y155 MX SCC-S26B-A KV-21SE42 RM-Y155 E SCC-S25D-A KV-21SE42C RM-Y155 E SCC-S25H-A KV-21SE82 RM-Y165 E SCC-S25J-A KV-21SE82C RM-Y165 E SCC-S25K-A

RM-Y155

MICROFILM

KV-21SE82

TRINITRON® COLOR TV

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/ 21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

SPECIFICA TIONS

KV-21MB42C,

KV-20M42

Power Requirements 120V 60Hz Number of inputs/outputs

Video

Audio Input

Audio Out

Speaker Output (W) 3W 3W 3Wx2 3W x 2 3Wx2 4Wx2 5Wx2

Power Consumption (W)

In Use (Max) 80W 80W 80W 90W 90W 90W 90W

In Standby 1W 1W 1W 1W 1W 1W 1W

Dimensions (W/H/D)

(mm)

(in)

Mass

2222222

------1

522 x 477 x 479 mm522 x 477 x 479 mm522 x 477 x 479 mm522 x 477 x 479 mm522 x 477 x 479 mm522 x 477 x 479 mm522 x 477 x 479

/8 x 1813/16 x

/8 in.

KV-21MB42M,

KV-21MB42P

AUTO VOLT

120-220V,

50/60 Hz

/8 x 1813/16 x

/8 in.

KV-21ME42,

KV-21ME42C

AUTO VOLT

120-220V,

50/60 Hz 120V 60 Hz

/8 x 1813/16 x

/8 in.

KV-20S42,

KV-20S43

/8 x 1813/16 x

/8 in.

KV-21SB42C, KV-21SB42M

AUTO VOLT

120-220V,

50/60 Hz

/8 x 1813/16 x

/8 in.

KV-21SE42,

KV-21SE42C

AUTO VOLT

120-220V,

50/60 Hz

/8 x 1813/16 x

/8 in.

KV-21SE82,

KV-21SE82C

AUTO VOLT

120-220V,

50/60 Hz

/8 x 1813/16 x

/8 in.

(kg) 21.6 kg 21.6 kg 21.6 kg 21.6 kg 21.6 kg 21.6 kg 21.6 kg

(lbs) 48 lbs. 48 lbs. 48 lbs. 48 lbs. 48 lbs. 48 lbs. 48 lbs.

Television system

American TV standard/NTSC

1 Vp-p 75 ohms unbal anced, sync negativ e

2 )

500 mVrms (100% modulation), impedance: 47 kilohms

More than 408 mVrms at the maximum volume setting (variable)

More than 408 mVrms (fix), Impedance: 5 kilohms

Picture tube

Trinitron® Tube

Channel coverage

VHF:2-13/UHF:14-69/CATV:1-125

Visible screen size

20" picture measured diagonally

Actual screen size

21" picture measured diagonally

Antenna

75 ohm external terminal for VHF/UHF

Supplied Accessories

Remote Commander (RM-Y155)

(KV-20S42/21SB42M/42C/21SE42/42C)

Remote Commander (RM-Y156)

(KV-20M42/21MB42C/42M/42P/21ME42/42C)

Remote Commander (RM-Y156W)

(KV-20S43)

Remote Commander (RM-Y165)

(•) SRS (SOUND RETRIEVAL SYSTEM)

(KV-21SE82/82C)

Size AA (R6) batteries (2)

Optional Accessories

Dipole antenna Connecting cables VMC-810S/820S, VMC-720M, YC-15V/30V, RK74A U/V mixer EAC-66

Design and specifications are subject to change without notice.

The (•) SRS (SOUND RETRIEVAL SYSTEM) is manufactured by Sony Corporation under license from SRS Labs, Inc. It is covered by U.S. Patent No. 4,748,669. Other U.S. and foreign patents pending.

The word ‘SRS’ and the SRS symbol (•) are registered trademarks of SRS Labs, Inc.

BBE and BBE symbol are trademarks of BBE Sound, Inc. and are licensed by BBE Sound, Inc. under U.S. Patent No. 4,638,258 and 4,482,866.

— 2 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Section Title Page

Warnings and Cautions..................................................................................................................................................4

Self-Diagnostic Function.................................................................................................................................................4

Safety Check Out Instructions........................................................................................................................................7

1. GENERAL............................................................................................................................................................8

2. DISASSEMBLY

2-1. Rear Cover Removal....................................................................................................................................................12

2-2. A Board Removal..........................................................................................................................................................12

2-3. Service Position............................................................................................................................................................12

2-4. Picture Tube Removal..................................................................................................................................................13

3. SET-UP ADJUSTMENTS

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

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

3-3. Focus............................................................................................................................................................................16

3-4. Screen (G2)...................................................................................................................................................................16

3-5. Method of Setting the Service Adjustment Mode.........................................................................................................16

3-6. White Balance Adjustments..........................................................................................................................................16

4. SAFETY RELATED ADJUSTMENTS

4-1. R582 Confirmation Method (HV Hold-Down Confirmation and Readjustments)....................................................17

4-2. B+ Voltage Confirmation and Adjustment....................................................................................................................17

5. CIRCUIT ADJUSTMENTS

5-1. Setting the Service Adjustment Mode..........................................................................................................................19

5-2. Memory Write Confirmation Method.............................................................................................................................19

5-3. Adjust Buttons and Indicators.......................................................................................................................................19

5-4. A Board Adjustments....................................................................................................................................................22

6. DIAGRAMS

6-1. Block Diagram...............................................................................................................................................................27

6-2. Circuit Board Location..................................................................................................................................................30

6-3. Printed Wiring Boards and Schematic Diagrams.........................................................................................................33

• A Board.....................................................................................................................................................................33

• C Board....................................................................................................................................................................42

6-4. Semiconductors............................................................................................................................................................43

7. EXPLODED VIEWS

7-1. Chassis (KV-20S43/21SE42/42C/82/82C/ME42/42C).................................................................................................44

7-2. Chassis (KV-20M42/S42/21MB42C/42M/42P/SB42C/42M)........................................................................................45

8. ELECTRICAL PARTS LIST ...........................................................................................................................47

Table of Contents for Parts List ...........................................................................................................................................47

A Board Common Parts Listing............................................................................................................................................48

C Board Parts List................................................................................................................................................................56

A Board Variant Parts Lists...................................................................................................................................................57

Packaging List and Accessories....................................................................................................................................................65

— 3 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/ 21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

WARNINGS AND CAUTIONS

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.

WARNING!!

AN ISOLATION TRANSFORMER SHOULD BE USED DURING ANY SERVICE TO AVOID POSSIBLE SHOCK HAZARD, BECAUSE OF LIVE CHASSIS. THE CHASSIS OF THIS RECEIVER IS DIRECTLY CONNECTED TO THE AC POWER LINE.

SAFETY-RELATED COMPONENT WARNING!!

COMPONENTS IDENTIFIED BY SHADING AND MARK ON THE SCHEMATIC DIAGRAMS, EXPLODED VIEWS, AND IN THE PARTS LIST ARE CRITICAL FOR SAFE OPERATION. REPLACE THESE COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS PUBLISHED BY SONY. CIRCUIT ADJUSTMENTS THAT ARE CRITICAL FOR SAFE OPERATION ARE IDENTIFIED IN THIS MANUAL. FOLLOW THESE PROCEDURES WHENEVER CRITICAL COMPONENTS ARE REPLACED OR IMPROPER OPERATION IS SUSPECTED.

SELF-DIAGNOSTIC FUNCTION

ATTENTION

APRES AVOIR DECONNECTE LE CAP DE L'ANODE, COURT-CIRCUITER L'ANODE DU TUBE CATHODIQUE ET CELUI DE L'ANODE DU CAP AU CHASSIS METALLIQUE DE L'APPAREIL, OU AU COUCHE DE CARBONE PEINTE SUR LE TUBE CATHODIQUE OU AU BLINDAGE DU TUBE CATHODIQUE.

ATTENTION!!

AFIN D'EVITER TOUT RESQUE D'ELECTROCUTION PROVENANT D'UN CHÁSSIS SOUS TENSION, UN TRANSFORMATEUR D'ISOLEMENT DOIT ETRE UTILISÉ LORS DE TOUT DÉPANNAGE. LE CHÁSSIS DE CE RÉCEPTEUR EST DIRECTEMENT RACCORDÉ À L'ALIMENTATION SECTEUR.

ATTENTION AUX COMPOSANTS RELATIFS A LA SECURITE!!

LES COMPOSANTS IDENTIFIES PAR UNE TRAME ET PAR UNE MARQUE SUR LES SCHEMAS DE PRINCIPE, LES VUES EXPLOSEES ET LES LISTES DE PIECES SONT D'UNEIMPORTANCE CRITIQUE POUR LA SECURITE DU FONCTIONNEMENT. NE LES REMPLACER QUE PAR DES COMPOSANTS SONY DONT LE NUMERO DE PIECE EST INDIQUE DANS LE PRESENT MANUEL OU DANS DES SUPPLEMENTS PUBLIES PAR SONY. LES REGLAGES DE CIRCUIT DONT L'IMPORTANCE EST CRITIQUE POUR LA SECURITE DU FONCTIONNEMENT SONT IDENTIFIES DANS LE PRESENT MANUEL. SUIVRE CES PROCEDURES LORS DE CHAQUE REMPLACEMENT DE COMPOSANTS CRITIQUES, OU LORSQU'UN MAUVAIS FONTIONNEMENT SUSPECTE.

The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY/TIMER LED will automatically begin to flash. The number of times the LED flashes translates to a probable source of the problem. A definition of the STANDBY/TIMER LED 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.

Diagnostic Test Indicators

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

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

Diagnostic Item

Description

Power does not turn on Does not light

+B overcurrent (OCP)* 2 times 2 :0 or 2: 1 • H.OUT (Q50 2) is sh orted (A Board)

Vertical deflection stopped* 4 times 4:0 or 4:1 • +13V is not supplied. (A Board)

White balance f ailure (not balanced)

No. of Times

STANDBY/TIMER

LED Flashes

5 times 5:0 or 5:1 • Video OUT (Q394 t o 392) is faulty. (A Board)

Self-diagnostic Display/

Diagnostic Result

Probable Cause

Location

• Po w er c ord is not plugged in.

• Fuse is burned out (F601).

• IC701 and Q70 1 (C Board) are shorted.

• IC541 is faulty. (A Board)

• IC301 is faulty. (A Board)

• Screen (G2) is im properly adjusted.**

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.

• Vertical deflectio n puls e is s to pped.

• Power line is shorted or power supply is stoppe d.

• No raster is generated.

• CRT cathode current detect ion reference pulse output is small.

* 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.

** Refer to Scr een (G2) Adjustments in Sections 3 and 4 of this manual.

— 4 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Display of Standby/Timer LED Flash Count

2 times 4 times 5 times

LED ON 0.3 sec. LED OFF 0.3 sec.

Diagnostic Item Flash Count*

+B overcurrent 2 times Vertical deflection stopped 4 times White balance failure 5 times

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

LED OFF

3 sec.

STANDBY/TIMER LED

Stopping the Standby/Timer LED Flash

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

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 occurrences of failure on the screen for confirmation.

To Bring Up Screen Test

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

Display Channel

Self Diagnostic Screen Display

SELF DIAGNOSTIC

2: 0 3: N/A 0 4: 0 5: 1 101: N/A 0

Sound volume

Numeral “0” means that no fault was detected.

Numeral “1” means a fault was detected one time only.

Power ON

Note that this differs from entering the service mode (sound volume

— 5 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/ 21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

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 when the diagnostic screen is displayed, as shown below:

ENTERChannel

Quitting the Self-Diagnostic Screen

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

Self-diagnostic Circuit

FROM

CRT

FROM

IC521 PIN 7

IC301

Y/CHROMA JUNGLE

IK IN

HP/PROTECT

SDA

IC541

V. OUT

REF

IC001

SYSTEM

IO-BDAT

O-LED

I-PROT

IO-SDAT

DISPLAY

IC003

MEMORY

B-DAT

+B overcurrent (OCP) Occurs when an overcurrent on the +B (115V) line is detected by pin 18 of IC301. If the voltage

of pin 18 of IC301 is less than 1V when V.SYNC is more than seven verticals in a period, the unit will automatically turn off.

V ertical deflection stopped Occurs when an absence of the vertical deflection pulse is detected by pin 17 of IC001. Power

supply will shut down when waveform interval exceeds 2 seconds.

White balance failure If the RGB levels* do not balance within 2 seconds after the power is turned on, 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 1K.)

— 6 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

Trouble Light

AC Outlet Box

Ohmmeter

Cold-water Pipe

SAFETY CHECK-OUT

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

After correcting the original service problem, perform the following safety checks before releasing the set to the customer:

1. Check the area of your repair for unsoldered or poorly soldered connections. Check the entire board surface for solder splashes and bridges.

2. Check the interboard wiring to ensure that no wires are “pinched” or touching high-wattage resistors.

3. Check that all control knobs, shields, covers, ground straps, and mounting hardware have been replaced. Be absolutely certain that you have replaced all the insulators.

4. Look for unauthorized replacement parts, particularly transistors, that were installed during a previous repair. Point them out to the customer and recommend their replacement.

5. Look for parts which, though functioning, show obvious signs of deterioration. Point them out to the customer and recommend their replacement.

6. Check the line cords for cracks and abrasion. Recommend the replacement of any such line cord to the customer.

7. Check the B+ and HV to see if they are specified values. Make sure your instruments are accurate; be suspicious of your HV meter if sets always have low HV.

8. Check the antenna terminals, metal trim, “metallized” knobs, screws, and all other exposed metal parts for AC leakage. Check leakage as described below.

Leakage Test

The AC leakage from any exposed metal part to earth ground and from all exposed metal parts to any exposed metal part having a return to chassis, must not exceed

0.5 mA (500 microampere). Leakage current can be measured by any one of three methods.

1. A commercial leakage tester, such as the Simpson 229 or RCA WT-540A. Follow the manufacturers' instructions to use these instructions.

2. A battery-operated AC milliammeter. The Data Precision 245 digital multimeter is suitable for this job.

3. Measuring the voltage drop across a resistor by means of a VOM or battery-operated AC voltmeter. The “limit” indication is 0.75 V, so analog meters must have an accurate low voltage scale. The Simpson’s 250 and Sanwa SH-63Trd are examples of passive VOMs that are suitable. Nearly all battery-operated digital multimeters that have a 2 VAC range are suitable (see Figure A).

How to Find a Good Earth Ground

A cold-water pipe is guaranteed earth ground; the coverplate retaining screw on most AC outlet boxes is also at earth ground. If the retaining screw is to be used as your earth ground, verify that it is at ground by measuring the resistance between it and a cold-water pipe with an ohmmeter. The reading should be zero ohms. If a coldwater pipe is not accessible, connect a 60- to 100-watt trouble light (not a neon lamp) between the hot side of the receptacle and the retaining screw. Try both slots, if necessary, to locate the hot side on the line; the lamp should light at normal brilliance if the screw is at ground potential (see Figure B).

To Exposed Metal Parts on Set

AC Voltmeter (0.75 V)

Earth Ground

Figure B. Checking for earth ground.Figure A. Using an AC voltmeter to check AC leakage.

— 7 —

SECTION 1 GENERAL

User Guide

Connecting Additional Equipment

TV and VCR

Connect the coaxial cable from your TV antenna or cable TV to the IN jack on your VCR.

Connect a coaxial cable (not supplied) from the OUT jack on your VCR to the VHF/UHF IN jack on the TV.

(Optional Connection)

If your VCR is equipped with video inputs, for best picture quality you should connect A/V connectors to AUDIO/VIDEO OUT on your VCR to AUDIO/VIDEO IN on your TV. You can use the button to switch between the TV and VCR inputs.

✍

To watch video programs from your VCR, tune your TV to channel 3 or 4 (as set on the rear of your VCR).

The instructions mentioned here are partial abstracts from the Operating Instruction

Manual. The page numbers shown reflect those of the Operating Instruction Manual.

Connecting Your TV

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Read this chapter before setting up your TV for the first time. This section covers basic connections in addition to any optional equipment you may be connecting.

Basic Connections

TV with indoor or outdoor antenna, or CATV cable

Depending on the cable available in your home, choose one of the connections below:

— 8 —

✍

If you are connecting to an indoor or outdoor antenna, it will be necessary to adjust the orientation of the antenna for best reception.

Connecting Your TV

User Guide

TV, VCR, and Cable box

Connect the coaxial cable from the wall to the IN jack on your cable box.

Connect a coaxial cable (not supplied) from the OUT jack on your cable box to the IN jack on your VCR.

Connect a coaxial cable from OUT on your VCR to VHF/UHF IN on your TV.

(Optional Connection)

✍

If you will be controlling all channel selection through your cable box, you should consider using the CHANNEL FIX feature on page 17.

TV and Cable Box

— 9 —

Connect the coaxial cable from the wall to the IN jack on your cable box.

Connect a coaxial cable (not supplied) from the OUT jack on your cable box to the VHF/UHF IN jack on the TV.

✍

To view channels from your cable box, tune your TV to channel 3 or 4 (as set on the rear panel of your cable box) and use the cable box’ s remote control to change channels.

✍

If you will be controlling all channel selection through your cable box, you should consider using the CHANNEL FIX feature on page 17.

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Connecting Your TV

Using the Remote Control and Basic Functions

This section shows you how to use more advanced buttons on the remote control and how to use the on-screen menus.

Turns the TV off automatically in approximately 30, 60 or 90 minutes. Cancel by pressing until SLEEP OFF appears.

Instantly turns off the sound. Press again or press to restore sound.

Cycles through the available video inputs. Press once to show current time, (if set) and channel number.

Press again to activate CAPTION VISION settings, if available. To cancel, press again until DISPLAY OFF appears.

Cycles through the Multi-Channel TV Sound (MTS) options: STEREO, SAP (Second Audio Programming) and MONO, (KV-20S42, 20S43 only).

Press for channel selection, the channel will change after 2 seconds.

Press after selecting a channel using the - buttons to immediately activate selection.

Alternates back and forth between the last two channels selected with the - buttons.

Displays the on-screen menu. Press again to exit the menu at any time.

Activates highlighted selections in the on-screen menu. Moves the cursor in the on-screen menu.

Press to restore factory settings while in the on-screen menu.

✍

Buttons shown are for remote control RM-Y155, your remote control may not look exactly like the one illustrated.

Connecting a Camcorder

Using A/V cables, connect AUDIO and VIDEO OUT on your camcorder to AUDIO and VIDEO IN on your TV.

(Front A/V Panel)

A/V output

— 10 —

✍

For model KV-13M42, this connection can be made to the A/V input located on the rear of the TV.

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Other Information

User Guide

If, after reading these operating instructions, you have additional questions related to the use of your Sony television, please call our Direct Response Center at 1-800-222-SONY (7669) (U.S. customers only) or (416) 499-SONY (7669) (Canadian customers only).

Cannot receive higher number channels (UHF) when using an antenna

❏ Make sure CABLE is set to OFF in the SET UP menu

(page 17).

❏ Use AUTO PROGRAM to add channels that are not

presently in the memory (page 17).

Cable stations don’t seem to work

❏ Make sure CABLE is set to ON in the SET UP menu

(page 16).

❏ Use AUTO PROGRAM to add channels that are not

presently in the memory (page 17).

Remote control does not operate

❏ Batteries could be weak. Replace them (page 2). ❏ Move the TV 3-4 feet away from fluorescent lights.

The TV needs to be cleaned

❏ Clean the TV with a soft dry cloth. Never use strong

solvents such as thinner or benzine, which might damage the finish of the cabinet.

Lost password for PARENTAL CONTROL

❏ In the password screen, enter the following master

password: 4357. After using the master password, you must create a new password, it cannot be used to unlock currently blocked programs.

Other Information

Troubleshooting

If you are having a problem with your TV, try the suggestions below. If the problem persists, contact your nearest Sony dealer.

No picture, no sound

— 11 —

Poor or no picture, good sound

Good picture, no sound

No color ❏ Adjust COLOR in the VIDEO menu (page 13). Only snow

appears on the screen

Dotted lines or stripes

Double images or ghosts

❏ Make sure the power cord is plugged in. ❏ If a red light is flashing on the front of your TV for

more than a few minutes, call your local service center.

❏ Check the TV/VIDEO settings: when watching TV , set

to TV; when watching video equipment, set to VIDEO (page 13).

❏ Check your PARENTAL CONTROL settings, (see

pages 22-23).

❏ Make sure the batteries have been inserted correctly

into the remote control.

❏ Try another channel, it could be station trouble. ❏ Adjust PICTURE in the VIDEO menu (page 13). ❏ Adjust BRIGHTNESS in the VIDEO menu (page 13). ❏ Check the antenna and/or cable connections (page 3). ❏ Press so that MUTING disappears from the

screen (page 9).

❏ Check your AUDIO settings. Your TV may be set to

SAP (page 14).

❏ Check the CABLE setting in the SET UP menu

(page 17).

❏ Check the antenna and/or cable connections (page 3). ❏ Make sure the channel selected is currently

broadcasting.

❏ Adjust the antenna. ❏ Move the TV away from other electronic equipment.

Some electronic equipment can create electrical noise, which can interfere with TV reception.

❏ Check your outdoor antenna or call your cable service.

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/ 21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

SECTION 2

DISASSEMBLY

2-1. REAR COVER REMOV AL

Rear Cover

Four Screws (BVTP 4x16)

2-2. A BOARD REMOVAL 2-3. SERVICE POSITION

C Board

Claw

A Board

— 12 —

2-4. PICTURE TUBE REMOV AL

WARNING:

BEFORE REMOVING

THE ANODE CAP

High voltage remains in the CRT even after the power is disconnected.

To avoid electric shock, discharge CRT before attempting to remove the anode cap. Short between anode and CRT coated earth ground strap.

Degaussing Coil

Tension Spring (B)

C Board

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Two Screws

Two Speaker Boxes (KV-21SE82/82C ONLY)

A Board

Tuner

Coated

Deflection Yoke

Four Tapping Screws

Anode Cap

Two Screws

Earth Ground Strap

Picture Tube

Cushion

ANODE CAP REMOV AL

WARNING: High voltage remains in the CRT even after the power is disconnected. To avoid electrical shock, discharge the CRT before

NOTE: After removing the anode, short circuit the anode of the picture tube and the anode cap to either the metal chassis, CRT shield,

attempting to remove the anode cap. Short between anode and coated earth ground strap of CRT.

or carbon painted on the CRT.

REMOVAL PROCEDURES

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

Use your thumb to pull the rubber cap firmly in the direction indicated by arrow

HOW TO HANDLE AN ANODE CAP

Do not use sharp objects which may cause damage to the surface of the anode cap.

To avoid damaging the anode cap, do not squeeze the rubber covering too hard. A material fitting called a shatter-hook terminal is built into the rubber.

Do not force turn the foot of the rubber cover. This may cause the shatter-hook terminal to protrude and damage the rubber.

— 13 —

Anode Button

When one side of the rubber cap separates from the anode button, the anode cap can be removed by turning the rubber cap and pulling it in the direction of arrow

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/ 21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

SECTION 3

SET -UP ADJUSTMENTS

The following adjustments should be made when a complete realignment is required or when a new picture tube is installed.

These adjustments should be performed with rated power supply voltage unless otherwise noted.

Set the controls and switch as follows unless otherwise noted.

PICTURE control ................. Normal

BRIGHTNESS control......... Normal

3-1. BEAM LANDING

Before beginning adjustment procedure:

1. Degauss the entire screen.

2. Feed in the white pattern signal.

Adjustment Procedure

1. Input a raster signal with the pattern generator.

2. Loosen the deflection yoke mounting screw and set the purity control to the center as shown below.

Perform the adjustments in order as follows:

1. Beam Landing

2. Convergence

3. Focus

4. Screen (G2)

5. White Balance

Note: Test equipment required:

• Color bar pattern generator

• Degausser

• DC power supply

• Digital multimeter

5. Move the deflection yoke forward and adjust so that the entire screen becomes green.

Purity Control

3. Turn the raster signal of the pattern generator to green.

4. Move the deflection yoke backward and adjust the purity control so that green is in the center and red and blue are at the sides evenly.

Blue Red

Green

6. Switch over the raster signal to red and blue and confirm the condition.

7. When the position of the deflection yoke is determined, tighten it with the deflection yoke mounting screw.

8. If landing at the corner is not right, adjust by using the disk magnets.

Purity control

corrects this area

Disk magnets

or rotatable disk

Deflection yoke positioning

corrects these areas

magnets correct

these areas (a-d)

— 14 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

3-2. CONVERGENCE

Before starting convergence adjustments:

1. Perform FOCUS, V .LIN AND V.SIZE adjustments.

2. Set BRIGHTNESS control to minimum.

3. Feed in dot pattern.

Vertical Static Convergence

1. Adjust V.STAT magnet to converge red, green and blue dots in the center of the screen (vertical movement).

Center dot

R G B

V.STAT magnet

If the blue dot does not converge with the red and green dots, perform the following:

1. Move BMC magnet (a) to correct insufficient H. Static convergence.

2. Rotate BMC magnet (b) to correct insufficient V. Static convergence.

3. In either case, repeat Beam Landing Adjustment.

PURITY

V. STAT

BMC MAGNET

BMC magnet

2. Tilt the V.STAT magnet and adjust static convergence to open or close the V.STAT magnet.

When the V.STAT magnet is moved in the direction of arrows

and , red, green, and blue dots move as shown

below:

(1)

(2) a

(3)

B G

BGR

RGB

B G

Dynamic Convergence Adjustment

Before performing this adjustment, perform Horizontal and Vertical Static Convergence Adjustment.

1. Slightly loosen deflection yoke screw.

2. Remove deflection yoke spacers.

3. Move the deflection yoke for best convergence, as shown below:

BGR

R G B

RGB

BGR

B G R

4. Tighten the deflection yoke screw.

5. Install the deflection yoke spacers.

RGB

BGR RGB

R G B

— 15 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

(G2)

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

Screen-Corner Convergence

1. Affix a permalloy assembly corresponding to the misconverged areas.

a-d: screen-corner

misconvergence cd

3-3. FOCUS

1. Adjust FOCUS control for best picture.

FOCUS

(FV)

SCREEN

3-5. METHOD OF SETTING THE SERVICE

ADJUSTMENT MODE

Service Mode Procedure

1. Standby mode (power off).

Display Channel

on the Remote Commander (press each button within a second).

Sound volume Power ON

Service Adjustment Mode In

1. The CRT displays the item being adjusted.

Disp.

Item

(Item)

Data

SERVICE HSIZ 0

2. Press or on the Remote Commander to select the item.

3. Press

or on the Remote Commander to change the

data.

4. Press

then to save into the memory.

Service Adjustment Mode Memory

Turn set off then on to exit service adjustment mode.

3-4. SCREEN (G2)

1. Input a dots pattern.

2. Set the PICTURE and BRIGHTNESS controls at minimum and COLOR control at normal.

3. Adjust SBRT, GCUT, BCUT in service mode with an oscilloscope as shown below so that voltages on the red, green, and blue cathodes are 170 VDC.

170 VDC

Ground

4. Observe the screen and adjust SCREEN (G2) VR to obtain the faintly visible background of dot signal.

Pedestal

SERVICE WRITE

MUTING

ENTER

Green

Red

3-6. WHITE BALANCE ADJUSTMENTS

1. Input an entire white signal.

2. Set to Service Adjustment Mode.

3. Set DCOL to “0”.

4. Set the PICTURE and BRIGHTNESS to minimum.

5. Adjust with SBRT if necessary.

6. Select GCUT and BCUT with

7. Adjust with

and for the best white balance.

8. Set PICTURE and BRIGHTNESS to maximum.

9. Select GDRV and BDRV with

10.Adjust with

and for the best white balance.

11.Reset DCOL to “1”.

12. To write into memory, press

and .

then .

— 16 —

KV-20M42/20S42/20S43/21MB42C/21MB42M/21MB42P/21ME42/21ME42C/

I ABL

ABL

T504

FBT

Range

Ammeter

3.0 mA DC

21SB42C/21SB42M/21SE42/21SE42C/21SE82/21SE82C

SECTION 4

SAFETY RELATED ADJUSTMENTS

4-1. R582 CONFIRMATION METHOD

(HV HOLD-DOWN CONFIRMATION) AND READJUSTMENTS

The following adjustments should always be performed when replacing the following components which are marked with

on the schematic diagram.

DY, C511, C574, C575, D572, D573, D574, R582, R583, R584, R585, R586, R578, R625, R626, R634, R635, T504, IC301, IC521, IC602

Preparation Before Confirmation

1. Turn the POWER switch ON. Input an entirely white signal and set the PICTURE and BRIGHTNESS controls to maximum.

2. Confirm that the voltage between C574 (+) and ground is more than 99.8 VDC when the set is operating normally with 120.0 ± 2.0 VAC (or 120-220±VAC for KV-21MB42C/42M/42P/ME42/42C/SB42C/42M/ SE42/42C/82/82C).

Hold-down Operation Confirmation

1. Connect the current meter between Pin 11 of the FBT (T504) and the PCB land where Pin 11 would normally attach. (See Figure 1 on the following page.)

2. Input a dot signal and set PICTURE and BRIGHTNESS to minimum: IABL = 95 + 100/-95mA.

3. Confirm the voltage of A Board TP-600 is

117.0 ± 0.3 VDC.

4. Connect the digital voltmeter and the DC power supply via diode 1SS119 to C574 (+) and ground (See Figure 1 on the following page).

5. Increase the DC power voltage gradually until the picture blanks out.

6. Read the digital voltmeter indication.

7. Turn DC power source off immediately: (standard: less than or equal to 127.3 VDC).

8. Input a white signal and set PICTURE and BRIGHTNESS to maximum: (standard: less than or equal to 127.3 VDC).

9. Repeat steps 4 to 7.

Hold-down Readjustment

If the setting indicated in step 2 of Hold-down Operation Confirmation cannot be met, readjustment should be performed by altering the resistance value of R582, a component marked with

4-2. B+ VOL TAGE CONFIRMATION AND

ADJUSTMENT

Note: The following adjustments should always be performed when replacing the following components, which are marked with

on the schematic diagram.

IC001, IC602, R030, R626, R632, R633, R635, R636, R637, R638, R639

1. Supply 120.0 ± 2.0 VAC (or 120-220±VAC for KV-21MB42C/42M/42P/ME42/42C/SB42C/42M/SE42/ 42C/82/82C) to the set with a variable auto transformer.

2. Input a dot signal.

3. Set the PICTURE and BRIGHTNESS controls to minimum.

4. Set to Service Adjustment Mode.

5. Select PADJ with

6. Adjust with

7. Confirm the voltage of A board TP-600 is less than 125 VDC.

8. If step 7 is not satisifed, replace the components and repeat the above steps.

9. Supply 120.0 ± 2.0 VAC (or 120-220±VAC for KV-21MB42C/42M/42P/ME42/42C/SB42C/42M/SE42/ 42C/82/82C) to the set with a variable auto transformer.

10.Adjust with

11.Press

and .

to the 0 level.

and for 117.0 ± .3 VDC.

then to save into the memory.

— 17 —

+ 38 hidden pages

SONY BA6 Diagram

TABLE OF CONTENTS

SAFETY CHECK-OUT

DISASSEMBLY

SET -UP ADJUSTMENTS

SAFETY RELATED ADJUSTMENTS