Sony HCD-DZ280 Service Manual page 3

MODEL IDENTIFICATION
– Back Panel –
Model
DZ280: AEP, UK model
HDZ284: CND model
HDZ485: CND model
HDZ485: PX model
DZ680: AEP, UK model
• Abbreviation
CND : Canadian model
SAFETY CHECK-OUT
After correcting the original service problem, perform the follow-
ing 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
Parts No.
The AC leakage from any exposed metal part to earth ground and
from all exposed metal parts to any exposed metal part having a
Part No.
return to chassis, must not exceed 0.5 mA (500 microamperes.).
4-113-457-0[]
Leakage current can be measured by any one of three methods.
4-113-457-2[]
1. A commercial leakage tester, such as the Simpson 229 or RCA
4-113-457-6[]
4-113-457-8[]
2. A battery-operated AC milliammeter. The Data Precision 245
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3. Measuring the voltage drop across a resistor by means of a
HCD-DZ280/DZ680/HDZ284/HDZ485
WT-540A. Follow the manufacturers' instructions to use these
instruments.
digital multimeter is suitable for this job.
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 μF
1.5 kΩ
Fig. A. Using an AC voltmeter to check AC leakage.
Ver. 1.1
AC
voltmeter
(0.75 V)
Earth Ground
3