STR-DA333ES, STR-DA555ES - Sony Audio Service Manual (repair manual). Page 3

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MODEL

PARTS No.

DA555ES:US model

4-219-066-0

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DA555ES:Canadian model

4-219-066-1

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DA333ES:US model

4-219-066-2

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DA333ES:Canadian model

4-219-066-3

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PART NO.

    After correcting the original service problem, perform the fol-
lowing safety checks 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.

    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 microampers). Leak-
age 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 pas-
sive 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

0.15 

µ

F

1.5 k

Ω

AC
Voltmeter
(0.75 V)

Earth Ground

Fig. A.  Using an AC voltmeter to check AC leakage.

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