"Arfa Daily" wrote in
:



On Apr 24, 10:25 pm, "ManhattanMan" wrote:
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.....

TIA



"Jerry G." wrote in message
..
. The HV diode cannot be properly checked with an ohm meter. The
breakover voltage required is too great. If the diode is opened there
is no way to know wiithout doing a proper voltage check. For this you
will require the proper HV probe. If the diode is shorted the HV
transformer would be overloading and most likely the fuse will be
blown.

Common causes of failures as what you are describing are from the
diode being opened, transformer failure filter capacitor failure, and
or magnetron failure.

I have a really old Sharp MW,and the HV cap failed(a big POP),but I
replaced the HV diode along with the cap for that reason. It still cost
only $25 for all the parts from the local appliance repair store.
That was several years ago,the MW is almost 30 yrs old now.

--
Jim Yanik
jyanik
at
kua.net