TC-L55E50
3
1 Safety Precautions
1.1.
General Guidelines
1. 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.
2. After servicing, see to it that all the protective devices such as insulation barriers, insulation papers shields are properly
installed.
3. After servicing, make the following leakage current checks to prevent the customer from being exposed to shock hazards.
4. When conducting repairs and servicing, do not attempt to modify the equipment, its parts or its materials.
5. 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.
6. When conducting repairs and servicing, do not twist the Faston connectors but plug them straight in or unplug them straight
out.
1.1.1.
Leakage Current Cold Check
1. Unplug the AC cord and connect a jumper between the
two prongs on the plug.
2. Measure the resistance value, with an ohmmeter,
between the jumpered AC plug and each exposed
metallic cabinet part on the equipment such as
screwheads, connectors, control shafts, etc. When the
exposed metallic part has a return path to the chassis, the
reading should be 100 Mohm and over.
When the exposed metal does not have a return path to
the chassis, the reading must be
.
1.1.2.
Leakage Current Hot Check (See
Figure 1.)
1. Plug the AC cord directly into the AC outlet. Do not use
an isolation transformer for this check.
2. Connect a 1.5kohm, 10 watts resistor, in parallel with a
0.15
μ
F capacitors, 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 an AC voltmeter, with 1000 ohms/volt or more
sensitivity, to measure the potential across the resistor.
4. Check each exposed metallic part, and measure the
voltage at each point.
5. Reverse the AC plug in the AC outlet and repeat each of
the above measurements.
6. The potential at any point should not exceed 0.75 volts
RMS. A leakage current tester (Simpson Model 229 or
equivalent) may be used to make the hot checks, leakage
current must not exceed 1/2 milliamp. In case a
measurement is outside 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
Summary of Contents for TC-L55E50-1
Page 36: ...TC L55E50 35 Cables Clampers Tapes A B C D E F G P4 LD GK4 P2 A02 SP R A12 SP L A12 A10 K10 ...
Page 37: ...TC L55E50 36 11 Schematic Diagram 11 1 Schematic Diagram Notes ...
Page 38: ...TC L55E50 37 11 2 A Board 1 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 39: ...TC L55E50 38 11 3 A Board 2 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 40: ...TC L55E50 39 11 4 A Board 3 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 41: ...TC L55E50 40 11 5 A Board 4 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 42: ...TC L55E50 41 11 6 A Board 5 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 43: ...TC L55E50 42 11 7 A Board 6 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 44: ...TC L55E50 43 11 8 A Board 7 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
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Page 51: ...TC L55E50 50 11 15 A Board 14 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
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Page 53: ...TC L55E50 52 11 17 A Board 16 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 54: ...TC L55E50 53 11 18 A Board 17 17 Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 55: ...TC L55E50 54 11 19 GK Board Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 56: ...TC L55E50 55 11 20 K Board Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 57: ...TC L55E50 56 11 21 P Board Schematic Diagram 6 5 4 3 2 1 A B C D E F G H I ...
Page 71: ...Model No TC L55E50 Parts Location ...
Page 72: ...Model No TC L55E50 Packing Exploded View 1 ...
Page 73: ...Model No TC L55E50 Packing Exploded View 2 ...
