High Voltage Capacitor - Panasonic NE-C1275 Service Manual

8.2.

High voltage capacitor

1. Check continuity of capacitor with ohmmeter on highest
OHM scale.
2. A normal capacitor will show continuity for a short time, and
then indicate 9MΩ once the capacitor is charged.
3. A shorted capacitor will show continuous continuity.
4. An open capacitor will show constant 9MΩ.
(Due to internal 9MΩ resistor)
5. Resistance between each terminal and chassis should be
infinite.
8.3. Diode
1. Isolate the diode assembly from the circuit by disconnecting
the leads.
2. With the ohmmeter set on the highest resistance scale,
measure the resistance across the diode terminals.
Reverse the meter leads and again observe the resistance
reading. A meter with 6V, 9V or higher voltage batteries
should be used to check the front-to-back resistance of the
diode, otherwise infinite resistance may be read in both
directions.
A normal diode's resistance will be infinite in one direction
and several hundred KΩ in the other direction.
8.4. Magnetron
Continuity checks can only indicate an open filament or a
shorted magnetron. To diagnose for an open filament or
shorted magnetron.
1. Isolate magnetron from the circuit by disconnecting the
leads.
2. A continuity check across magnetron filament terminals
should indicate one ohm or less.
3. A continuity check between each filament terminal and
magnetron case should read open.
8.5. Membrane key board
(Membrane switch assembly)
Check continuity between switch terminals, by pressing an
appropriate pad on the key board.
The contacts assignment of the respective pads on the key
board is as shown in the schematic diagram of DPC.
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NE-C1275 / NE-C1475