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SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK ! OR DOTTED LINE WITH
MARK ! ON THE SCHEMATIC DIAGRAMS 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.ATTENTION AU COMPOSANT AYANT RAPPORT
Ë LA SƒCURITƒ!
LES COMPOSANTS IDENTIFƒS PAR UNE MARQUE ! SUR LES
DIAGRAMMES SCHƒMATIQUES ET LA LISTE DES PIéCES SONT
CRITIQUES POUR LA SƒCURITƒ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIéSES SONY
DONT LES NUMƒROS SONT DONNƒS DANS CE MANUEL OU
DANS LES SUPPƒMENTS PUBLIƒS PAR SONY.
TABLE OF CONTENTS
After correcting the original service problem, perform the
following safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, ÒmetallizedÓ knobs, screws,
and all other exposed metal parts for AC leakage. Check leakage as
described below.
LEAKAGE
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 microampers).
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 manufacturersÕ instructions to use these
instruments.
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 ÒlimitÓ indication
is 0.75 V, so analog meters must have an accurate low-voltage
scale. The Simpson 250 and Sanwa SH-63Trd are examples of
a passive VOM that is suitable. Nearly all battery operated
digital multimeters that have a 2V AC range are suitable. (See
Fig. A)
SAFETY CHECK-OUT
To Exposed Metal
Parts on Set
0.15
µF 1.5k ½
AC
voltmeter
(0.75V)
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
1. GENERAL ááááááááááááááááááááááááááááááááááááááááááááááááááá\
ááááááááááááááááááá 4
2. TEST MODEááááááááááááááááááááááááááááááááááááááááááááááááááá\
ááááááááá 6
3. DIAGRAMS
3-1. Circuit Boards Location ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áá 7
3-2. Block Diagram Ñ Main Section Ñ ááááááááááááááááááááááááááááááááááá 9
3-3. Block Diagram Ñ Power Section Ñ ááááááááááááááááááááááááááááááá 11
3-4. Printed Wiring Board Ñ AMP Section Ñ ááááááááááááááááááááááá 13
3-5. Schematic Diagram Ñ AMP Section Ñ áááááááááááááááááááááááááá 15
3-6. Printed Wiring Board Ñ Video Section Ñ áááááááááááááááááááááá 17
3-7. Schematic Diagram Ñ Video Section Ñ ááááááááááááááááááááááááá 19
3-8. Printed Wiring Board Ñ Input Section Ñ ááááááááááááááááááááááá 21
3-9. Schematic Diagram Ñ Input Section Ñ áááááááááááááááááááááááááá 23
3-10. Printed Wiring Board Ñ Display Section Ñ ááááááááááááááááááá 25
3-11. Schematic Diagram Ñ Display Section Ñ áááááááááááááááááááááá 27
3-12. Printed Wiring Board Ñ Power Section Ñ ááááááááááááááááááááá 29
3-13. Schematic Diagram Ñ Power Section Ñ áááááááááááááááááááááááá 31
3-14. IC Block Diagrams ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááá 35
4. EXPLODED VIEWS
4-1. Front Panel Section ááááááááááááááááááááááááááááááááááááááááááááááááááá\
ááááááá 38
4-2. Chassis Section ááááááááááááááááááááááááááááááááááááááááááááááááááá\
áááááááááááááá 39
5. ELECTRICAL PARTS LIST ááááááááááááááááááááááááááááááááááá 40
