Does the fan motor work when you shut the door and turn the timer?
YES
Does the oven lamp light? NO
Does the turntable turn?
YES
Normal reading should be approx. 0
Replace or repair oven lamp, turntable motor.
If microwave do not oscillate, check continuity of filament of magnetron.
Poor continuity
NO Continuity
Check continuity
filament tap (3.3V)
of high voltage transformer.
Continuity
Check continuity filament tap (3.3V)
of high voltage transformer.
Continuity
No Continuity
Continuity in the reverse direction.
Replace high voltage transformer
Replace high voltage diode
Replace magnetron
Meter with 600V or higher voltage Meger should
be used to check the normal direction resistance of
the diode
Check the isolation of filament winding of high voltage transformer.
Good
NO Continuity
Replace high voltage transformer.
Replace magnetron
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