Microwave quit working no display nothing. Serviceman said it blew the
20 A fuse.
He replaced the fuse turned it on and for about one second made a buzzing sound and blew the fuse again. By the sound it made he claimed it was the magnetron. So I replace the magnetron (pn MAC 58001218)
turned it on and made the same noise and then blew the fuse again.
The buzzing noise sounds like the high voltage transformer. Could it be the transformer or another defective part causing that noise or that part causing the transformer to make that noise? I noticed that the light in the oven dimmed during the noise right before the fuse blew. Not sure what part that is bad…
The transformer is fine, it’s the HV capacitor that is bad.
Here is the diagram----->Model JMC8100ADB
Section 4 item#16 is the capacitor
When removing will i have to be careful for electrical shock that might be stored in the capacitor?
No, the cap is already shorted, so you don’t need to short it out. But if you want to, get 2 screwdrivers. Put one on one terminal then the other on the other terminal of the cap, and touch the screwdriver shafts together.
Thank you Senior Expert
I am going to order part and give it a try…
let you know if things are a go…
In my experiance in this situation, a shorted transformer will trip the house breaker. A shorted capacitor will blow a fuse. A magnetron tube will not blow a fuse or house breaker.
This thread seems to explain the situation I just experienced with my Jenn Air JMC8100AD. While operating, suddenly emitted loud buzzing for 2-3 seconds, then dead…no display or any sign of life. Didn’t trip house breaker. I haven’t opened it up to see if internal fuse is blown.
Is it safe to assume it’s the HV capacitor, as in the unit described previously? If so, should I assume the fuse is blown and order that at the same time?
Thanks.