TX-PR65VT20 - Panasonic Plasma Service Manual (repair manual). Page 3

3

1. When conducting repairs and servicing, do not attempt to modify the equipment, its parts or its materials.
2. When wiring units (with cables, flexible cables or lead wires) are supplied as repair parts and only one wire or some of the

wires have been broken or disconnected, do not attempt to repair or re-wire the units. Replace the entire wiring unit instead.

3. When conducting repairs and servicing, do not twist the Fasten connectors but plug them straight in or unplug them straight

out.

4. When servicing, observe the original lead dress. If a short circuit is found, replace all parts which have been overheated or

damaged by the short circuit.

5. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly

installed.

6. After servicing, make the following leakage current checks to prevent the customer from being exposed to shock hazards.

1. Plug the AC cord directly into the AC outlet. Do not use an isolation transformer for this check.
2. Connect a measuring network for touch currents between each exposed metallic part on the set and a good earth ground

such as a water pipe, as shown in Figure 1.

3. Use Leakage Current Tester (Simpson 228 or equivalent) to measure the potential across the measuring network.
4. Check each exposed metallic part, and measure the voltage at each point.
5. Reserve the AC plug in the AC outlet and repeat each of the above measure.
6. The potential at any point (TOUCH CURRENT) expressed as voltage U

1

 and U

2

, does not exceed the following values:

For a. c.: U

1

 = 35 V (peak) and U

2

 = 0.35 V (peak);

For d. c.: U

1

 = 1.0 V,

The limit value of U

2

 = 0.35 V (peak) for a. c. and U

1

 = 1.0 V for d. c. correspond to the values 0.7 mA (peak) a. c. and 2.0

mA d. c.
The limit value U

1

 = 35 V (peak) for a. c. correspond to the value 70 mA (peak) a. c. for frequencies greater than 100 kHz.

7. In case a measurement is out of the limits specified, there is a possibility of a shock hazard, and the equipment should be

repaired and rechecked before it is returned to the customer.

Figure 1