Panasonic PT-40LC12 User manual

Order No. MKE0204850C1
B2
Multi Media Display
PT-40LC12 / PT-45LC12
SPECIFICATIONS
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1. SAFETY PRECAUSIONS
1.1. GENERAL GUIDELINES
1. For continued safety, no modification of any circuit should be
attempted.
2. Disconnect AC Plug before disassembling this unit.
3. It is advisable to use an isolation transformer in the AC supply before
servicing.
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, shield, and isolation R-C
combinations etc. are properly installed.
6. After servicing, be sure to restore the wires, leads, insulation barriers,
shields, etc.
7. After servicing, make the leakage current checks to prevent the
customer from being exposed to shock hazards.
Caution:
Use a separate Isolation Transformer for this unit when servicing.
1.2. 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
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jumpered AC plug and each exposed metallic cabinet part on the
receiver, such as screwheads, connectors, etc. When the exposed
metallic part has a 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.
1.3. 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.
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 V RMS.
A leakage current tester (Simpson Model 229 equivalent) may be used
to make the hot checks. Leakage current must not exceed 1/2 mA. In
case a measurement is outside of the limits specified, there is a
possibility of shock hazard, and the receiver should be repaired and
rechecked before it is returned to the customer.
Figure 1
1.4. UV-PRECAUTION
1. Be sure to disconnect the AC Plug when replacing the lamp.
2. Since the lamp reaches a very high temperature during its operation,
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wait until it has completely cooled off when replacing the Lamp Unit.
3. The lamp emits small amounts of UV-Radiation.
Avoid direct-eye contact by covering the Lamp and wearing the UV cut
protective glass.
4. The high pressure lamp involves a risk of explosion. Therefore, do not
touch the Lamp Bulb when servicing.
Figure 2
2. PREVENTION OF ELECTROSTATIC DISCHARGE
(ESD) TO ELECTROSTATICALLY SENSITIVE (ES)
DEVICES
Some semiconductor (solid state) devices can be damaged easily by static electricity. Such
components commonly are called Electrostatically Sensitive (ES) Devices. Examples of typical ES
devices are integrated circuits and some field-effect transistors and semiconductor "chip"
components. The following techniques should be used to help reduce the incidence of component
damage caused by electro static discharge (ESD).
1. Immediately before handling any semiconductor component or
semiconductor-equipped assembly, drain off any ESD on your body by
touching a known earth ground. Alternatively, obtain and wear a
commercially available discharging ESD wrist strap, which should be
removed for potential shock reasons prior to applying power to the
unit under test.
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2. After removing an electrical assembly equipped with ES devices, place
the assembly on a conductive surface such as aluminum foil, to
prevent electrostatic charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or unsolder ES
devices.
4. Use only an antistatic solder removal device. Some solder removal
devices not classified as "antistatic (ESD protected)" can generate
electrical charge sufficient to damage ES devices.
5. Do not use freon-propelled chemicals. These can generate electrical
charges sufficient to damage ES devices.
6. Do not remove a replacement ES device from its protective package
until immediately before you are ready to install it. (Most replacement
ES devices are packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable conductive material).
7. Immediately before removing the protective material from the leads of
a replacement ES device, touch the protective material to the chassis
or circuit assembly into which the device will be installed.
CAUTION :
Be sure no power is applied to the chassis or circuit, and observe all
other safety precautions.
8. Minimize bodily motions when handling unpackaged replacement ES
devices. (Otherwise harmless motion such as the brushing together of
your clothes fabric or the lifting of your foot from a carpeted floor can
generate static electricity (ESD) sufficient to damage an ES device).
3. OPERATION GUIDE
4. SERVICE NOTES
5. DISASSEMBLY/ASSEMBLY PROCEDURES
5.1. CABINET SECTION
5.2. LARGE VIEW FOR DISASSEMBLY/ASSEMBLY OF CABINET
6. SERVICE FIXTURES AND TOOLS
7. TROUBLESHOOTING HINTS
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8. BLOCK DIAGRAMS
9. SCHEMATIC DIAGRAMS
9.1. SCHEMATIC DIAGRAM AND CIRCUIT BOARD LAYOUT NOTES
9.2. INTERCONNECTION SCHEMATIC DIAGRAM
9.3. FRONT JACK SCHEMATIC DIAGRAM
9.4. RGB JACK / OPERATION SCHEMATIC DIAGRAMS
9.5. AUDIO POWER / LAMP THERMISTOR / FRONT THERMISTOR / LAMP
COVER SWITCH SCHEMATIC DIAGRAMS
9.6. WAVEFORMS
10. CIRCUIT BOARD LAYOUT
10.1. FRONT JACK C.B.A. / RGB JACK C.B.A. / OPERATION C.B.A.
10.2. AUDIO POWER C.B.A. / LAMP THERMISTOR C.B.A. / FRONT
THERMISTOR C.B.A. / LAMP COVER SWITCH C.B.A.
11. EXPLODED VIEWS
11.1. MAIN PARTS SECTION (1)
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11.2. MAIN PARTS SECTION (2)
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11.3. BASE FRAME SCTION
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11.4. TV FARME SECTION
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11.5. PACKING PARTS AND ACCESSORIES SECTION
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