Leakage Test - Sony HCD-GX25 Service Manual

HCD-GX25
Tuner section
FM stereo, FM/AM superheterodyne tuner
FM tuner section
Tuning range 87.5 – 108.0 MHz
Antenna FM lead antenna
Antenna terminals 75 ohm unbalanced
Intermediate frequency 10.7 MHz
AM tuner section
Tuning range 530 – 1,710 kHz (with the tuning
interval set at 10 kHz)
Antenna AM loop antenna
Antenna terminals External antenna terminal
Intermediate frequency 450 kHz
General
Power requirements 120 V AC, 60 Hz
Power consumption 120 watts
Dimensions (w/h/d) Approx. 280 × 325 × 407 mm
Mass Approx. 8.5 kg
Supplied accessories: AM loop antenna (1)
Remote Commander (1)
Batteries (2)
FM lead antenna (1)
Speaker pads (8)
Design and specifications are subject to change without
notice.
2
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)
To Exposed Metal
Parts on Set
0.15µF
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.
AC
1.5k Ω
voltmeter
(0.75V)
Earth Ground