Table Of Contents - Sony STR-K675P Service Manual

STR-K675P
SAFETY CHECK-OUT
After correcting the original service problem, perform the following
safety check before releasing the set to the customer:
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
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 2 V AC range are suitable. (See
Fig. A)
To Exposed Metal
Parts on Set
0.15 µ F
Fig. A. Using an AC voltmeter to check AC leakage.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0 OR DOTTED LINE
WITH MARK 0 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.
2
AC
1.5 k Ω
voltmeter
(0.75 V)
Earth Ground

TABLE OF CONTENTS

1. GENERAL
................................................................... 3
2. TEST MODE
............................................................... 7
3. DIAGRAMS
3-1. Block Diagram - MAIN Section - .............................. 10
3-2. Block Diagram - DISPLAY/POWER Section - ........ 11
3-3. Printed Wiring Board
- DIGITAL Board (Side A) - ...................................... 12
3-4. Printed Wiring Board
- DIGITAL Board (Side B) - ...................................... 13
3-5. Schematic Diagram - DIGITAL Board (1/4) - .......... 14
3-6. Schematic Diagram - DIGITAL Board (2/4) - .......... 15
3-7. Schematic Diagram - DIGITAL Board (3/4) - .......... 16
3-8. Schematic Diagram - DIGITAL Board (4/4) - .......... 17
3-9. Printed Wiring Board - MAIN Section - ................... 18
3-10. Schematic Diagram - MAIN Section (1/3) - ............. 19
3-11. Schematic Diagram - MAIN Section (2/3) - ............. 20
3-12. Schematic Diagram - MAIN Section (3/3) - ............. 21
3-13. Printed Wiring Board - STANDBY Section - ........... 22
3-14. Printed Wiring Board - DISPLAY Section - ............. 23
3-15. Schematic Diagram - DISPLAY Section - ................ 24
3-16. Printed Wiring Board - VIDEO Board - .................... 25
3-17. Schematic Diagram - VIDEO Board - ...................... 26
4. EXPLODED VIEWS
4-1. Front Panel Section ......................................................... 34
4-2. Chassis Section ................................................................ 35
5. ELECTRICAL PARTS LIST
Notes on chip component replacement
• Never reuse a disconnected chip component.
• Notice that the minus side of a tantalum capacitor may be
damaged by heat.
UNLEADED SOLDER
Boards requiring use of unleaded solder are printed with the lead-
free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with
the lead free mark due to their particular size)
: LEAD FREE MARK
Unleaded solder has the following characteristics.
• Unleaded solder melts at a temperature about 40 °C higher
than ordinary solder.
Ordinary soldering irons can be used but the iron tip has to be
applied to the solder joint for a slightly longer time.
Soldering irons using a temperature regulator should be set to
about 350 °C.
Caution: The printed pattern (copper foil) may peel away if
the heated tip is applied for too long, so be careful!
• Strong viscosity
Unleaded solder is more viscou-s (sticky, less prone to flow)
than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
• Usable with ordinary solder
It is best to use only unleaded solder but unleaded solder may
also be added to ordinary solder.
.................................. 36