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SECTION 1 SERVICING NOTES
MODEL IDENTIFICATION � Rear view � 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)
PART No.
MODEL DE 335: US model DE 335: Canadian model DE 335: Australian model DE 335: Malaysia, Singapore models V 323 DE 335: E model DE 335: AEP model SE 391 PART No. 4-218-844-0[] 4-218-844-1[] 4-218-844-2[] 4-218-844-3[] 4-218-844-4[] 4-218-844-5[] 4-218-844-6[] 4-218-844-7[]
4321
To Exposed Metal Parts on Set
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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