Table Of Contents - Sony TA-AV411 Service Manual

TA- AV411 :
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 0.5mA (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 instru-
ments.
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 volt-
meter. 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)
To Exposed Metal
Parts on Set
AC
voltmeter
(0.75 V)
Earth Ground
. Using an AC voltmeter to check AC leakage.
TABLE OF CONTENTS
Section Title Page
SPECIFICATIONS Cee emer acer esr ee nesensecreserereeesuees 1
1. GENERAL eee eee ee Re ie ee a ee ee 3
2. DIAGRAMS
2-1. Description on IC101( ¢PD75206-717-3BE) -::-- 6
2-2. Key operation i ee er 8
2-3. MATRIX for FL tube and KEY IN-:::--+:::: 12
2-4. Description on IC303 (LV1001M)----++++++++: 14
2-5. Circuit Boards Location «+++ +sseseer ee eeeeees 16
2-6. Semiconductor Lead Layouts::+++++ereseeeeees 17
2-7. Printed Wiring BoardsS:sceercersceceescvcsevcee 18
2-8. Schematic Diagram err ee er ee eee ee ee ee ee 23
2-9. IC Block Diagrams Cece ease cnensesneseencanseces 26
3. EXPLODED VIEWS
3-1. Overall Section Lessserseseeceeccescresceceeecs 27
3+ 2. Overall "Section 2 se1etserieritse des pastes re 28
6. ELECTRICAL PARTS LIST --+-+++eesseeereeeeeees 29
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK A OR DOTTED
LINE WITH 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 PUB-
LISHED BY SONY.