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These servicing instructions are for use by qualifi ed service personnel only. To reduce the risk of electric shock, do not perform any 
servicing other than that contained in the operating instructions unless you are qualifi ed to do so.

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. 

Ces instructions de service sont à l’usage du personnel de service qualifi é seulement. Pour prévenir le risque de choc électrique, ne 
pas faire l’entretien autre que celui contenu dans le Mode d’emploi à moins que vous soyez qualifi é faire ainsi.

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.

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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.

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.

The units in this manual contain a self-diagnostic function. If an error occurs, the POWER/STANDBY or LAMP 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 POWER/STANDBY or LAMP LED fl ash 
indicators is listed in the instruction manual for the user’s knowledge and reference. If an error symptom is diffi cult to reproduced use the Remote 
Commander to display the record that is stored at the internal NVM to specify the cause of the failure.

Diagnostic Test Indicators
When an error occurs, the POWER/STANDBY or LAMP 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. If the errors occur simultaneously, the one that corresponds to the fewest 
fl ashes is identifi ed fi rst.
Results for all of the following diagnostic items are displayed on screen.  No error has occurred if the screen displays a “0”.

Lamp cover error

 3 times

- Lamp cover is not fastened securely

- No picture/No sound

Fan error

4 times

- Fan1-4 Power is not supplied.(G2 board)
- Fan connector is not seated securely
- Fan caught wires or harnesses

- No picture/No sound

Temp error

4 times

- Internal temperature is too high
- IIC-E line connector is not seated properly
  (WE:H3 board, WF/XS:H4 board) 

- No picture/No sound

Lamp driver error

5 times

- Lamp driver defect

- No picture/No sound

Low B error

6 times

-No  "DD 6V " output (G1 board)

- No picture/No sound

Audio error

7 times

- Short-circuit of Audio power supply line
   (KD board, G1 board)
- Blowout of a fuse 
   (F4702,F4703,F4704 on KD board)
- IC failure 
   (IC4703,IC4708,IC4710 on KD board)

- No picture/No sound

D-OVP error

8 times

-  Overvoltage of +3.3V or +2.5V 
   (A board, B board)

- No picture/No sound

ATSC-OVP error

10 times

-No "DTL MODULE 5V " output 
   (G1 board, G2 board)

- No picture/No sound

Lamp error

LAMP-LED is ON.

- Lamp is dead

- No picture/No sound

POWER

PRO

STD/DUO

LAMP

TIMER

POWER/STANDBY

Screen

Proj ection  lamp

Indi cat ors

Proj ection l amp

Indicators

For K DF-WE655 seri es

For KDF-WF655 series

- Oneflash is not usedfor self-diagnosis.

- Example

Diagnosis

Number of times LED Flash

Lamp cover

3 times

Fan

4 times

LED ON : 0.3 sec
LED OFF : 0.3sec

LED OFF

3.0sec

Releasing the POWER/STANDBY LED Flash
Unplug the power cord from the outlet to temporarily stop the POWER/STANDBY lamp from fl ashing.

Self-Diagnosis Screen Display
For failures that are diffi cult to reproduce, or accompany occasional power off and/or picture mute, the Self-Diagnosis screen display is useful to 
specify the cause..

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

1.  Display  

  Channel  5      

 Sound Volume  -  

 Power ON

SELFCHECK

1 : LAMP ERR

0

3 :
4 :

LAMP COVER

0

 FAN-E/TEMP-E

1

5 : LAMP DRIVER
6 : LowB-ERR

0

0

7 : Audio-Prot
8 : D-OVP

0

1

101 : WDT

0

10

: ATSC_OVP

0

"1" is displayed when a failure is detected one or more times
"0" is displayed when no failure has been detected

 
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”.