"ManhattanMan" writes:

4 year old sharp microwave that overnight decided it'd do everything but
heat.

All functions normal, except heat. There is 120V applied to the HV
transformer primary, secondary measures 150 ohm, filament on both
transformer and magnetron shows negligible ohms, diode tests good on back
voltage, HV cap appears OK, magnatron does get very hot after a couple of
ten second tests...... ?????

I've had several with bad micro switches, HV cap, etc., but this one does
everything but heat for no reason.....

My guess would be magnetron. Since it's getting hot quickly, it means it's
getting more than filament power, but not putting anything out.

But check he HV diode properly as described in another post or
at the S.E.R FAQ site below, or replace it. It will have a 6-10
V forward drop, so a VOM or DMM can't test it.

And the SAFETY issues are extremely critical!

--
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