GE Profile Microwave not heating

Microwave Repair
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1

I have a GE Profile Microwave/Oven Combo. The Model Number is JTP85WOA5WW
Serial # HA670514Q
Manufactured May 2001

The microwave portion has a problem. The lights work, clock works, everything from the control panel seems fine. When I try to cook something, the lights, turntable and everything are functioning. The unit gives off an hot electrical odor and nothing gets cooked. It also seems to be humming slightly louder than when it was in working order. I removed the capacitor and diode. The capacitor reads a perfect 950nf that matches the .95uf on the label. I checked the diode with a transistor battery. I put one leg of the diode on the battery and put my voltage meter on the other leg and back to the other terminal of the battery. I got 9 VDC checking one way, reversed the diode and got 0 VDC the other way, so the diode looks good. I tried to check the windings of the HV Transformer. The input side (measuring resistance across black and white has continuity and checking to ground it had 4.25K Ohms. The output side across the Magnetron showed continuity and had no continuity to ground. There was another wire that went from the transformer right to the capacitor (by itself) and it measured 80 Ohms to ground.
Then I measured the magnetron terminals with the harness disconnected. I get 37 ohms to ground on each terminal. This puzzles me. I would think they should be open. Does anyone know if the transformer readings look right? What should the Magnetron read? I know how to get measurements but don’t know what readings indicate failure for sure. Any idea? HELP!

2

I have the same symptoms you describe form my GE Cabinet Mount Model JVM2070SH001. I have not taken any volt / ohm / continuity measurements though.

Did anyone ever provide additional information as to what the problem might be? Mine is still not working and I would like to diagnose the problem also.

Thanks

Stack-D

3

I went to a parts store and they let me test some magnatrons there with my ohmeter. All of the new ones I checked showed open from the contacts to the case. Mine was showing 37 ohms. They happened to have a replacement for the one I had so I took it and installed it. Everything now works fine.

4

I checked my warranty and sure enough, the Magnatron was in fact the only thing that had a warranty for 10 years. So called the 1-800 number and had them send me the magnetron unit free of charge, and I went ahead and ordered the diode also, just for safe measure.

Replaced both of these, (even though the diode seemed fine). Plugged the unit back in with all the covers off, and for some reason it would not work, or at least the turn table would not turn. So then was thinking it may be the power supply / transformer, as my old magnetron seemed to test good when checking the contacts to chassis ground. But once I put it all back together, covers in place and all screwed back together, ran it again and it worked. So replacing the magnatron (and diode as recommended) is what I replaced to fix my unit.

Thanks all, and AppliancePartsPros.com for all the good info and help for fixing my 2003 unit.

Cheers,
Stack-D