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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.

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 manµFacturers’ 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

AC Voltmeter
(0.75 V)

Earth Ground

0.15 

µ

F

1.5 

k

Ω

g

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 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.

 

Front Panel Control Button
(1)fi INPUT

(2)fi Volumefi-

(3)fi Volumefi+

(4)fi Channelfi-

(5)fi Channelfi+

LED Indicator
(1)fi TimerfiLED

(2)fi PicturefiOfffiLED

(3)fi PowerfiLED

Control Button
(1)fi Powerfi(|)

LED Display
This model displays Power Supply Lamp in Green and Standby/Off-Timer Lamp in Red. Use the following tables to determine the status of the monitor.

Green On 

Off 

Off 

Microprocessor is in normal working 

mode. 

Red On 

Off 

Off 

Microprocessor is in sleeping mode. 

Green Blink 

Off 

Off 

 

Green On 

Red On 

Off 

 

Red Blink 

Off 

Off 

Causes of the failures are classified by 

red blink method. (See Failure LED 

Display table) 

Off Off 

Off 

 

Off Off  Blue 

On 

 

Scalar failure 

RED (2.0 sec.) 

→

 Off (2.0 sec.) 

Main Unit 

temperature failure 

RED (1.0 sec.) 

→

 Off (1.0 sec.) 

Power Supply failure 

RED (1.5 sec.) 

→

 Off (0.5 sec.) 

 Twenty-two screws

    (+BVTP 4x16)

 Six screws

    (+PSW 5x16)

 Rear cover

 Stand

1

3

2