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Panasonic microwave buzzing noise

Have a Panasonic NN-S669S. When I turn it on it makes a buzzing noise but does not heat. Is this indicative of a bad diode? If so where is it on this model? Can it be replaced?

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Re: Panasonic microwave buzzing noise

Yes, this is usually a shorted high voltage rectifier diode.

It is usually located behind the high voltage transformer and it attaches to the magnetron and to the chassis.

For ciritical safety links how to test the diode, see:
Panasonic replacement parts can be found here:

Posted on Dec 06, 2007

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