Panasonic TH-42PA20U/P, Service Manual

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Components identified by mark have special characteristics important for safety.
When replacing any of these components, use only manufacture's specified parts.
Important Safety Notice
Notes:
1. Resistor
All resistors are cabon 1/4W resistor, unless marked as follows:
Unit of resistance is OHM [
W
] (K=1,000, M=1,000,000).
: Nonflammable : Metal Oxide
: Solid : Metal Film
: Wire Wound : Fuse:
2. Capacitor
All capacitors are ceramic 50V capacitor, unless marked as follows:
Unit of capacitance is
m
F, unless otherwise noted.
: Temperature Compensation : Electrolytic
: Polyester : Bipolar
: Metalized Polyester : Dipped Tantalum
: Polypropylene : Z-Type
3. Coil
Unit of inductance is
m
F, unless otherwise noted.
4. Test Point
: Test Point position
5. Earth Symbol
: Chassis Earth (Cold) : Line Earth (Hot)
6. Voltage Measurement
Voltage is measured by a DC voltmeter.
Conditions of the measurement are the following:
Power Source ...................................................AC120V, 50/60Hz
Receiving Signal ............................................... Colour Bar signal (RF)
All customer's controls ...................................... Maximum positions
7. Number in red circle indicates waveform nember.
(See waveform pattern table.)
8. When arrow mark ( ) is found, connection is easily found from the direction of arrow
9. Indicates the major signal flow. : Video Audio
10. This schematic diagram is the latest at the time of printing and subject to change without
notice.
+ -
M
m T
Z
NP
TH-42PA20U
Schematic Diagram Notes
Remarks:
1. The Power Circuit contains a circuit area which uses a separate power supply to isolate the
earth connection.
The circuit is defined by HOT and COLD indications in the schematic diagram. Take the
follwing precautions.
All circuits, except the Power Circuit, are cold.
Precautions
a. Do not touch the hot part or the hot and cold parts at the same time or you may
be shocked.
b. Do not short- circuit the hot and cold circuits or a fuse may blow and parts may
break.
c. Do not connect an instrument, such as an oscilloscope, to the hot and cold
circuits simultaneously or a fuse may blow.
Connect the earth of instruments to the earth connection of the circuit being
measured.
d. Make sure to disconnect the power plug before removing the chassis.
2. Following diodes are interchangeable.
MA150- MA162 (Replacement part)
TH-42PA20U
Schematic Diagram Notes
14 Block and Schematic Diagrams
14.1. Schematic Diagram Notes
55