[OrgChem]

My GE microwave oven is not heating and when in the cabinet enclosure was making a loud humming noise. However the front panel seems to be functional. I've measured the continuity of my diode both ways and it measures ~5 ohms. I guess it is shorted out? Can the diode breakdown without losing other components, e.g. magnetron, capacitor, transformer? I have not tested the transformer but have measured the resistance of both the capacitor and magnetron and they seem to respond in the way I've read on some other website. Thanks for any help!

[Gene]

The diode is bad, no doubt about it. In most cases replacing the diode should solve the problem.

- The part number for the diode is AP3192533

Gene.

[OrgChem]

Thanks Gene. It's on order.

Steve

[Gene]

You're welcome. Keep us posted.

Gene.

[OrgChem]

Hi Gene,

I received my new GE HV diode and was surprised to see that it measured infinity across both polarities(used the diode check function). I am using a Craftsman 82334 multimeter (uses a 9V battery) to do the measurments. Thinking that perhaps this was the case where my multimeter was inaccurate I put the diode into the microwave oven anyway. However the oven did again not heat. Is it likely I get a defective diode or should I probe further? I have been following the enclosed GE troubleshooting guide and I think my HVT is okay. The HVC measured the specs 0.912 microfarads. Before I spring for the relatively expensive magnetron I would like to exhaust less expensive options. Thanks in advance of any help.
Steve

[abadfish66]

Org, there really are'nt any less expensive options. Your HV side is coming on, so transformer is good, cap is good magnetron is bad. Hopefully you did not ruin the good diode, cause alot of times, a bad magnetron will take the diode out with it. Hope this helps

[Gene]

Agreed with abadfish66. Unfortunately, sounds like the magnetron is bad. If the microwave is less than 5 years old than the part is still under the limited manufacturer warranty (part only).

- The part number for the magnetron is AP3191536

I would recommend to call GE to find out if they can ship the part to you and, if not, what is their labor charge.

Gene.

[OrgChem]

Thanks Gene and Abadfish66. Unfortunately GE will not send a replacement magnetron even though it is still under warrenty (9 years). This only applies to qualified GE repair service (either in home or bringing the unit to a GE qualified repair shop). The latter I have not been able to find in my area (upper Fairfield county, CT) and in home service will be quite costly. Anyway I guess that the magnetron can go bad in other ways than beyond the less than 1 ohm resistance across the filament terminals and infinite resistance from filament terminal to magnetron housing? With my measurements the magnetron passed the latter two tests. Thanks for any advice.
Steve

[Gene]

Steve,

The magnetron could be bad even if it shows correct resistance.

Your decision whether to fix the microwave or just buy a new one should be based on condition of the unit and price for a new microwave.

Gene.

[OrgChem]

I'm keeping my fingers crossed but I think my microwave is back online. I opted to replace the magnetron after having replaced the diode. I was then able to set a 3 min heat cycle and get a most excellent bag of popped popcorn. Actually it seemed to work better than before going heating silent! Is that my imagination or is it possible? Just one other question. Is there a quick and dirty procedure for testing microwave leakage? I would like to make sure I didn't do something that makes that an issue. I think I saw in my web searching some qualitative tests based on neon? Thanks again.
Steve