SONY STRNX3
Instrukcja Serwisowa

SECTION 1 SERVICING NOTES
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 lowvoltage 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

� MODEL IDENTIFICATION � Rear Panel �
PART No.

MODEL NX1: AEP, UK and Korean models NX1: US and Canadian models NX1: Malaysia, Singapore, Thai and Tourist models NX3: AEP, UK, Korean and Australian models NX3: US and Canadian models NX3: Malaysia and Singapore models

PART No. 4-221-391-0[] 4-221-391-1[] 4-221-391-2[] 4-221-391-3[] 4-221-391-4[] 4-221-391-5[]

0.15 µF

1.5 k�

AC voltmeter (0.75 V)

Earth Ground

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

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