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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.

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 identifi ed 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 identifi ed in this manual. Follow these procedures 
whenever critical components are replaced or improper operation is suspected. 

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 la couche de carbone peinte sur le tube cathodique ou au blindage du tube cathodique.

Afi n d’eviter tout risque 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 du secteur.

! 

Les composants identifi es par une trame et par une marque ! sur les schemas de principe, les vues explosees et les listes de 
pieces sont d’une importance 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 identifi es dans le present manuel. Suivre ces procedures lors de 
chaque remplacement de composants critiques, ou lorsqu’un mauvais fonctionnement suspecte.

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 specifi ed 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 microamperes). 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 milliampmeter. 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 a guaranteed earth ground; the cover-plate 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 cold-water 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

0.15  F

1.5 K 

Ω

AC

Voltmeter

(0.75 V)

Earth Ground

Trouble Light

AC Outlet Box

Ohmmeter

Cold-water Pipe

Figure A. Using an AC voltmeter to check AC leakage.

Figure B. Checking for earth ground.

*If a +B overcurrent is detected, stoppage of the vertical defl ection is detected simultaneously.  The symptom that is diagnosed fi rst by the 
mircrocontroller is displayed on the screen.
**Refer to Screen (G2) Adjustments in Section 2-4. of this manual.

 

+B Overcurrent 

 

2 times

 

Vertical Defl ection Stopped  4 times

 

White Balance Failure 

5 times

 

*One fl ash count is not used for self-diagnostic.

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 LAMP from fl ashing.

The units in this manual contain a self-diagnostic function. If an error occurs, the STANDBY/TIMER LED will automatically begin to fl ash. The number 
of times the LED fl ashes translates to a probable source of the problem. A defi nition of the STANDBY/TIMER LED fl ash 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 fl ash 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 fi rst 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”.

Power does not turn on 

+B overcurrent (OCP)* 

Vertical Defl ection
Stopped

White Balance failure
(not balanced)

Does not light

2 times

4 times

5 times

2:0 or 2:1

4:0 or 4:1

5:0 or 5:1

• Power cord is not plugged in.
• Fuse is burned out (F601). (A Board)

• H.OUT (Q502) is shorted.(A Board)
• IC1751 (C Board) is shorted.

• +13V is not supplied. (A Board)
• IC541 is faulty. (A Board)

• Video OUT (Q392 to Q394) is faulty. 

(A Board)

• IC301 is faulty.  (A Board)
• Screen (G2) is improperly 

• 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 defl ection pulse is stopped.
• Power line is shorted or power supply is stopped.

• No raster is generated.
• CRT Cathode current detection reference pulse       

output is small.

Self-Diagnostic Screen Display
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confi rmed, it is possible to bring up 
past occurrences of failure on the screen for confi rmation.

To Bring Up Screen Test
In standby mode, press buttons on the Remote Commander sequentially, in rapid succession, as shown below:

Display  

  Channel  5      

 Sound Volume  -  

 Power ON

Numeral “0” means that no fault was detected.
Numeral “1” means a fault was detected one time only.

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:

Channel  8  

  ENTER

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.

+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. 
Vertical Defl ection Stopped 
Occurs when an absence of the vertical defl ection 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).

Note that this differs from entering the Service Mode (Sound Volume  +  ).

IC301

Y/CHROMA JUNGLE

IC541

V. OUT

IC001

SYSTEM

IC003

MEMORY

IK IN

FROM

CRT

HP/PROTECT

SDA

FROM

IC521

PIN 7

18

IO-SDAT

O-LED

REF

I-PROT

IO-BDAT

BDA

DISPLAY

21

35

3

17

37

18

36

5