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SECTION 1 SERVICING NOTES
MODEL IDENTIFICATION � Specification Label � 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 microampers.). 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)
MODEL NO. TA-P9000ES MULTI CHANNEL PRE AMPLIFIER
SERIAL NO. MADE IN JAPAN
US, Canadian models : AC 120V 60Hz 20W AEP model : AC 220 - 230V 50/60Hz 20W
Notes on chip component replacement � Never reuse a disconnected chip component. � Notice that the minus side of a tantalum capacitor may be damaged by heat.
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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