I have a Whirlpool old model # RM278BXV-3 and it has started shutting all the way down when heating things up. Contol panel goes blank and quits heating.

My immediate reaction would be to cut your losses and buy a new unit as sooner or later you will run into a part that is no longer available.

ur magnetron is faulty

what is the problem with it im guessing it prob doesnt heat, if so prob need to get acess inside and check components i would recommend getting a service call as some componoents inside are still live even when unplugged,, it might require a magnetron which would be fairly expensive but if u dont wana replace it than i guess its your only option.. hope this helps

I just repaired mine with the same symptoms. I found that the bottom microswitch on the door (there are 3 switches) was faulty. It started as open, when the door closed, the switch closed (good), but when the door was fully closed the switch was open again. I went to Electronic City with the switch in hand, they found me a duplicate that cost me $2.50. BTW - you must take out the door switch assembly, 3 screws plus wires, in order to work on the switch. Also, put the assembly back in so that the door latches close/open the switches correctly. -jk

It's probably the Magnetron. They usually go out.
Most older ovens have a fuse that goes out with it and shuts the unit down. A repair shop should be able to replace the Magnetron at a reasonable cost.

You probably have a failed thermistor / temperature sensor.

There should be a "mini-manual" (tech sheet) hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting, testing, and locating components.

At our Web site, we have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

You can find helpful exploded view diagrams and order parts by entering your full model number here.

If you need to remove it from the wall, you can download GE installation instructions here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

It could be one of several things. A defective diode, triode, high-voltage capacitor, or even a faulty magnetron. Find your appliance model number, go to, http://www.apwagner.com and put your number in the model search. They should have breakdowns of many most current models. This way you can know what is what and what to look for. Good luck

You can usually find helpful exploded view diagrams and order parts by entering your full model number here.

We have critical safety information and disassembly information at our site, and our link is at our listing here on FixYa.

At our site, we now have a video available showing how to remove a typical control panel assembly in under 5 minutes.

There should also be a "mini-manual" hidden inside the unit behind the control panel or hidden on the left side behind the grille, which is very helpful when troubleshooting & testing.

Feel free to contact me directly.

We're happy to help you and we'd appreciate your thoughtful rating of our answer.

William E. Miller
[email protected]
http://www.microwavedisplay.com

Not clear what to explain but would look at the front control switches, commond problem, to see just play with the door open and closing to see what happen's with the fan, it's probroly not making proper contact, the other problem I can thing of is bad thermal heat sensor, there should be two or three of them, you need to know the basic what they do to test them just jump them, and try the unit and see if the problem stop to see witch termal is deffective.

Hope this help

Bob The builder

check the magnetron and related circuit and high voltage fuse and high voltage diodes, etc..