17 V
110 (Cold chassis ground)
6. When the TV set is not used for a long period of time, unplug the
power cord from the AC outlet.
7. Potentials, as high as 32.0 kV are present when this TV set is in
operation. Operation of the TV set without the rear cover involves
the danger of a shock hazard from the TV set power supply.
Servicing shouldnot be attempted by anyone who is not
thoroughly familiar with the precautions necessary when working
on high voltage equipment. Always discharge the anode of the
picture tube to the CRT ground of receiver before handling the
tube.
8. After servicing make the following leakage current checks to
prevent the customer from being exposed to shock hazards.
LEAKAGE CURRENT COLD CHECK
1. Unplug the AC cord and connect a jumper between the two prongs
on the plug.
2. For physically operated power switches, turn power on. Otherwise
skip step 2.
3. Measure the resistance value, with an ohmmeter, between the
jumpered AC plug and each exposed metallic cabinet part on the
receiver, such as screwheads, connectors, etc. When the exposed
metallic part hasa return path to the chassis, the reading should
be between 1 M and 12 M . When the exposed metal does not
have a return path to the chassis, the reading must be infinity.
LEAKAGE CURRENT HOT CHECK
1. Plug the AC cord directly into the AC outlet.
Do not use a isolation transformer for this check.
2. Connect a 1.5 k , 10 W resistor, in parallel with a 0.15 F
capacitor, between each exposed metallic part on the set and a
good earth ground , as shown in Figure 1.
3. Use an AC voltmeter, with 1 k /V or more sensitivity, to measure
the potential across the resistor.
3
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