Sony str de 425 service manual

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Dimensions 430 x 145 x 295 mm
Mussmpprox.) STR-DEAZS: 7.9 kg
Supplied FM wire aerial (1)
accessories AM loop aerial (1)
Remote controller (remote) (1)
Size AA (R6) hatteries (2)

Design and specifications are subject to change without notice.
Specifications indicated are measured at 230 VAC, 50 Hz

SAFETY CHECK-OUT

After correcting the original service problem, perform the
following safety checks before releasing the set to the customer:
Check the antenna terminals, metal trim, metallized knobs, screws,
and all other exposed metal parts forAC 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 manufacturers 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 limit" 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)

n: EmosedMeta/
Pam on Set
AC
0.15uF:: $1.510 my
': Earth Ground

Fig. A. UsinganAC voltmeterto checkAC leakage.

SAFETY-RELATED COMPONENT WARNING

COMPONENTS IDENTIFIED BY MARKA OR DOTI'ED LINEWITH
MARK A 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.

TABLE OF CONTENTS
1. GENERAL ............................................................... 3

2, TEST MODE ............................................................ 4

3. DIAG RAMS
3.1, Circuit Boards Location .............................................
3.2. Block Diagram ...............................
3-3. Schematic Diagram - Display Section -
3-4. Printed Wiring Board - Display Section -
3-5. Schematic Diagram - Power Section -
3-6. Printed Wiring Board - Power Section -
3»7. Printed Wiring Board - Main Section -
3-8. Schematic Diagram - Main Section (1/3) -
3-9. Schematic Diagram ~ Main Section (2/3)
3-10. Schematic Diagram 7 Main Section (3/3)
3-11. IC Pin Function Description
3-12. IC Block Diagrams -----------

. EXPLODED VIEWS
4-1. Front Panel Section ..
4-2. Chassis Section ------

5. ELECTRICAL PARTS LIST ------------------------------- 31

ATTENTION Au COMPOSANT AYANT RAPPORT
A LA sEcunITE!

LEs COMPOSANTS IDENTIFEs PAR UNE MAROUE A SUR LEs
DIAGRAMMES scuEMATIOUEs ET LA LISTE DES PIECES SONT
CRITIQUES POUR LA SECURITE DE FONcTIONNEMENT, NE
REMPLACER CES COMPOSANTS QUE PAR DES PIESEs SONY
DONT LEs NUMERos SONT DONNEs DANS CE MANUEL ou
DANS LES SUPPEMENTs PUBLIEs PAR SONY.

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