Panasonic NNS335BF - MICROWAVE - 0.8CUFT, Service Manual

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CAUTION
1. High voltage is present at the high voltage terminal of the high
voltage transformer during any cook cycle.
2. It is neither necessary nor advisable to attempt measurement of the
high voltage.
3. Before touching any oven components, or wiring, always unplug
the oven from its power source and discharge the high voltage
capacitor.
8.1. Primary Latch Switch, (Door
Switch and Power Relay B)
Interlocks.
1. Unplug the lead connectors to Power Relay B and verify
continuity of the power relay B 1-2 terminals.
2. Unplug lead connectors to primary Latch switch and Door
Switch.
3. Test the continuity of switches at door opened and closed
positions with ohm meter (low scale).
Normal continuity readings should be as follows.
8.2. Short Switch & Monitor
1. Unplug lead wires from H.V.transformer primary terminals.
2. Connect test probes of ohm meter to the disconnected
leads of the H.V. Transformer.
3. Test the continuity of short switch with door opened and
closed positions using lowest scale of the ohm meter.
Normal continuity readings should be as follows.
8.3. High voltage transformer
1. Remove connectors from the transformer terminals and
check continuity.
2. Normal (cold) resistance readings should be as follows:
Secondary winding........................... Approx. 80
Ω
~120
Ω
Filament winding.............................. Approx. 0
Ω
Primary winding................................. Approx. 0
Ω
~1
Ω
8.4. High voltage capacitor
1. Check continuity of capacitor with meter on highest OHM
scale.
2. A normal capacitor will show continuity for a short time, and
then indicate 9M
Ω
once the capacitor is charged.
3. A shorted capacitor will show continuous continuity.
4. An open capacitor will show constant 9M
Ω
.
5. Resistance between each terminal and chassis should be
infinite.
8 COMPONENT TEST PROCEDURE
13
NN-S335BF / NN-S335WF / NN-S335WM /