You cannot check a HV diode.
The only way for a microwave is to chek the HV at the cap, and the
filament some 10 A.

Cursitor Doom a écrit le 25/03/2019 Ã* 21:52Â*:
On Mon, 25 Mar 2019 13:20:41 -0400, Ralph Mowery wrote:

What did you use to check the diode ? Many of the high voltage diodes
are actually several in series in the same package. Most meters will
not check them as there are several volts dropped across them.
The meters will often show them as open in both directions evenif they
are good.
I used a 9v battery and just checked for low-res one way and high-res the
other. Totally dead in both directions.