Sony CDP-557ESD - Safety Check-out; Leakage Test Procedure

TABLE OF CONTENTS
Section Title Page
SPeCiiCatiONns. 434-6 wa et eat whe de ote A ]
Model Identification ................0.. 2
TGATULOS: 4,4: cn dove eed a os ied & Gene a hs 2
matety Check-OUT 25: fick 2 ae aka & Ske Bs 3
DELVICING NOK. 6 cin SS ee cule oe et PR eg 4
Location of Controls................... 5
EF DISASSEMBLY
Nut of Vplume Removal ............ 6
2. ELECTRICAL ADJUSTMENTS
Adjustment Mode................. 7
RF PLL Adjustment ............... e
Focus Bias Adjustment ............. 8
E-F Balance Adjustment ............ 8
Reference — Focus/Tracking Gain
Adjustment ............ 000000008 9
Distortion Adjustment.............. 10
= 3 DIAGRAMS
3-1. Optical Pcik-Up Block
Mounting Diagram ................ 11
3-2. IC Block Diagrams ................ 13
Dd~ WAVELOPINS: us oq. aiaes chee Ki Oe OE Se 16
3-4. Main Section Mounting Diagram ....... 18
3-5. Main Section Schematic Diagram ....... 23
3-6. Display Section Mounting Diagram ..... 28
3-7. Semiconductor Lead Layouts ......... 28
3-8. Display Section Schematic Diagram ..... 31
4. EXPLODED VIEWS AND
PAR TS: LISS: ota 244}. oad eas 33
5, ELECTRICAL PARTS LIST......... 40
Troubleshooting Guide ................. 48
CDP-557ESD/707ESD
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.
i)
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.