Panasonic CT30WC14J - 30" COLOR TV, Service Manual

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control shafts, etc. If the exposed metallic part has a returnpath to the chassis, the reading should be
between 240kΩ and 5.2MΩ. If the exposed metallic part does not have a return path to the chassis, the
reading should be infinite.
Leakage current hot check
Plug the AC cord directly into the AC outlet. Do not use an isolation transformer during the check.
Connect a 1.5kΩ 10 watt resistor in parallel with a 0.15μF capacitor between an exposed metallic part
and ground. Use earth ground, for example a water pipe.
Using a DVM with a 1000 ohms/volt sensitivity or higher, measure the AC potential across the
resistor.
Repeat the procedure and measure the voltage present with all other exposed metallic parts.
Verify that any potential does not exceed 0.75 volt RMS. A leakage current tester (such a Simpson
model 229, Sencore model PR57 or equivalent) may be used in the above procedure, in which case
any current measure must not exceed 0.5 milliamp. Ifany measurement is out of the specified limits,
there is a possibility of a shock hazard and the receiver must be repaired and rechecked before it is
returned to the customer.
Hot check circuit
Insulation test
Connect an insulation tester between an exposed metallic part and A.C. line. Apply 1500VAC/60Hz
for 1 second. Confirm that the current measurement is 0.5mA ~ 2.0mA. Repeat test with other
metallic exposed parts.
X ray radiation
WARNING
The potential source of x ray radiation in the TV set is in the high voltage section and the picture tube.
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