We have a GE Microwave that, on occasion, makes a loud buzzing sound (not a high-pitched buzz but a lower pitched buzz/almost grinding-type sound) and seems to flicker or spark. This sound and light comes from the upper right side of the microwave cavity. I checked the wave guide cover and it is clean, as is the rest of the interior of the microwave. I'm guessing it might be the diode, based on the descriptions of it making a loud buzzing noise when it goes. However the sparking/flickering isn't mentioned in anything I've read. Any ideas you might have would be helpful.
ANSWER Hello Mark,
The sparking is either a spot in the cooking compartment reflecting microwaves or the magnetron is failing. Most of the experience I've had with a low frequency hum has followed back to the high voltage transformer. The parts are not listed for this unit because the parts cost more than the replacement of the entire microwave. I regret to be the one to tell you that this unit is not financially feasible to repair.
Answered by AppliancePartsPros.com | Friday, May 04, 2012