Author Options:

how can i fix my microwave it stopped warming food? Answered


Just a thought, you haven't accidently started pressing "TIMER" instead of "COOK" have you?

How embarrassing...I've done that.

but at least I'm candid enough to admit it. ;-)

"There's mines over there, there's mines over there too, and watch out those goddamn monkeys bite, I'll tell ya!"
Seriously though, there is some truth to the stories of danger and death lurking beneath the cover of your microwave oven.  The supply to the magnetron tube is something in the range of 5000V at around 200 mA, so you definitely don't want to touch anything in there while the thing is plugged in . Then there's the story of HV capacitor which retains a charge, at a voltage of circa 5000 V, for some amount of time while the power is turned off.

Regarding whatever it is that is stopping your microwave from working: there are several switch-like elements, all in series, which may fail.  There's a fuse. Sometimes there is  a thermo-switch, or thermal fuse, to make sure the oven cavity doesn't get too hot.  Always there are interlock switches, a safety feature to make sure the door is closed before energizing the microwave generating circuits.

Often times there will be printed circuit diagram, printed on paper, pasted to one of the inside surfaces of the metal cover.  This can be helpful.

There are also resources like this one:

The repair FAQ linked above has some other safety tips, e.g. for discharging the HV capacitor, etc.  In fact it might be prudent to read that guide first.

Also this question has been asked of the Instructables Answers forum before:

Dont mess with a microwave oven unless you have years experience with electronics.  There are parts inside that can shock you or kill you if you touch wrong parts when they are charged up.  Some can retain charge even when unplugged.  Besides that, new microwave ovens are so cheap, its not worth fooling with.  If you do manage to fix it, you may have disabled a safety function... such as a door-open-shut-off switch.  Very dangerous.  If you decide to mess with it... do lots of research on HOW to do it and what to watch out for.... but I think   it is a bad idea to mess with. (PS... i am an electronics technician 30 years experience).

Check fuses VERY VERY carefully, apart from that, its probably scrap.


Yep, and remember there are a lot of goodies that can be salvaged from a wasted microwave.

+1 sad to say, but that's part of the modern experience. You *might be able to fix it, but it is likely less expensive to just buy a new one.