Follow up to: Unit shuts off (JVM1340WW002) and blows fuses

The service manual is here.

You can order parts from Encompass here.

It may be a bad monitor interlock / short switch, or possibly a shorted capacitor or other problem in the inverter.

But I'm surprised the 20A fuse is not blowing before the breaker is!

I hope it's on at least a 30A breaker...

Let me know if I can help further.

Sorry to read about your problem, I hope this helps you out.

you have a defective control board

I tried to help you. Please help me and Rate/Vote on my response, thanks and good luck

If it blows the fuse as soon as you hit the START button, it's almost certainly a shorted high-voltage capacitor.

If it blows a few seconds after you hit the START button, it's probably the high-voltage transformer. You'll possibly also smell a faint electrical burning smell from the rear vent after you shut if off.

If it blows the fuse as soon as it's plugged in, you probably have a shorted door switch, a shorted varistor, or an internally exposed wire shorting to the chassis, etc.

If it blows the fuse as soon as you hit the START button, it's almost certainly a shorted high-voltage capacitor.

If it blows a few seconds after you hit the START button, it's probably the high-voltage transformer. You'll possibly also smell a faint electrical burning smell from the rear vent after you shut if off.

If it blows the fuse as soon as it's plugged in, you probably have a shorted door switch, a shorted varistor, or an internally exposed wire shorting to the chassis, etc.

My GE spacesaver microwave all of a sudden stopped heating up things. The lights, fan, turntable, etc. work, but nothing is heating up. Any suggestions?

If it blows the fuse as soon as you hit the START button, it's almost certainly a shorted high-voltage capacitor.

If it blows a few seconds after you hit the START button, it's probably the high-voltage transformer. You'll possibly also smell a faint electrical burning smell from the rear vent after you shut if off.

Microwave can be very dangerous so it is best to have it looked by a professional

 

Would appreciate a solved rating for expert advise.

If the fuse blows as soon as you hit START, then it's likely that you have a shorted high-voltage capacitor. If the fuse blows a few seconds after you hit START, then it's likely that you have an overheating / shorting high-voltage transformer. If you or a friend decide to work on it, we have *critical* safety, disassembly, and troubleshooting info at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk You can find helpful exploded view diagrams and order parts by entering your model number here: http://tinyurl.com/gv383

Here's the overview on fuse blows:

If the fuse blows as soon as you plug the oven in the wall, or when you open the door, the problem is likely with the door switches.

If the fuse blows as soon as you hit START, then it's likely that you have a shorted high-voltage capacitor.

If the fuse blows a few seconds after you hit START, then it's likely that you have an overheating / shorting high-voltage transformer.

If you or a friend decide to work on it, we have *critical* safety, disassembly, troubleshooting info, door switch info, etc. at our site: http://www.microwavecontrol.com

> My question: Could they be right about the transformer and magnetron? It certainly could be the transformer or the magnetron, but I really don't think so. Not that I'm recommending that an inexperienced or unqualified person should do this - and bearing in mind that any person who would do so must assume ALL liability for injury or damage - here's how I (on a VERY careful day *grin*) would find out: - I would disconnect the oven's power cord from the wall - I would remove the outer cover - I would discharge the high voltage capacitor - I would look again to be sure the plug is out of the wall - I would make a careful note of and/or mark the exact connections of the wires going to the HV capacitor - I would be very careful in case the connectors have positive locks and not yank on them before I push in the locks - I would disconnect the wires from HV capacitor - I would set my meter to a medium or high resistance scale and touch one probe to each capacitor terminal and from each terminal to the case of the capacitor - If either reading held steady at less than infinity I would replace the capacitor, reconnect the wires, reassemble and test - If neither reading held steady at less than infinity I would reconnect the wires - I would then make a careful note and/or mark the exact locations of the wires attached to the transformer - I would then disconnect just the lead which goes from the secondary of the transformer to the capacitor - I would then remove the other end of that lead wire - I would then insert a new fuse then plug the microwave into the wall and test it - If the fuse blew, I would know it's not the capacitor or the magnetron and I would troubleshoot further - If the fuse did not blow, I would know it's the magnetron or the capacitor (but I just measured the capacitor and it's not shorted!! *grin*) - I would unplug it again from the wall - I would install a new capacitor, hook it all back up, install a new fuse, reconnect the wires, and test it again Sorry to be so stiff about my reply, but I do not want to advise or suggest that an untrained or inexperienced should troubleshoot or work on a microwave oven. The voltages can be instantly lethal. Good luck and be safe!!!

WARNING: Microwave ovens are the most dangerous consumer appliance to service due to up to 5,000 V at high current inside. Even with the power off, there is a HV capacitor that can produce a lethal kick. This capacitor must be discharged before touching anything in the microwave generator circuitry. DON'T remove the cover yourself unless you fully undertand the SAFETY issues involved in working inside a microwave oven. A microwave oven is possibly THE MOST DANGEROUS common consumer product to service. About the only "easy" fix would be a blown fuse, if it keeps blowing, don't go any further unless you know what you are doing. Your likely options are a blown high voltage cap, diode, or the magnetron. Good luck(but luck has nothing to do with it ;] )