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TABLE OF CONTENTS
1. GENERAL
Main unit ................................................................................. 4
Remote button description ....................................................... 5
2. DISASSEMBLY
2-1. Case ..................................................................................... 6
2-2. Front Panel Section ............................................................. 7
2-3. Back Panel ........................................................................... 7
2-4. Main Board ......................................................................... 8
3. TEST MODE ........................................................................ 9
4. DIAGRAMS
4-1. IC Pin Description ............................................................. 10
4-2. Circuit Boards Location .................................................... 11
4-3. Block Diagram - Main Section -...................................... 12
4-4. Block Diagram - Power Section -.................................... 13
4-5. Printed Wiring Board - Main Section -............................ 14
4-6. Printed Wiring Boards - H/P, Outlet Section -................. 15
4-7. Schematic Diagram - Main Section (1/2) -...................... 16
4-8. Schematic Diagram - Main Section (2/2) -...................... 17
4-9. Schematic Diagram - Display Section -........................... 18
4-10. Printed Wiring Board - Display Section -........................ 19
4-11. Printed Wiring Board - Power SW Section -................... 20
5. EXPLODED VIEWS
5-1. Case Section ...................................................................... 21
5-2. Front Panel Section ........................................................... 22
5-3. Chassis Section ................................................................. 23
6. ELECTRICAL PARTS LIST ......................................... 24
STR-DE185
1.5 k -¦ 0.15 Β΅F AC
voltmeter
(0.75 V) To Exposed Metal
Parts on Set
Earth Ground
Fig. A. Using an AC voltmeter to check AC leakage.
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 2V AC range are suitable. (See Fig. A)
