Chosen Solution

My Frigidaire microwave oven is not heating. The countdown timer runs as if it was heating, but that’s about it. Any suggestions?

The kind of failure described in this section could be due to failure of the magnetron tube, the power relay that supplies the magnetron tube, or the high voltage supply for the magnetron, especially if the turntable, fan, light and controls all still appear to be working. I recently resurrected a dead G.E. Profile built-in microwave oven whose power transformer had failed in a most smoky and smelly fashion. The display and touch pad control still appeared to work, but it didn’t heat anymore. The fuse didn’t blow. After the oven was taken down and the skins were removed, the failed part was visually obvious. Even though it was 5 years old and well out of warranty, we were able to get a replacement transformer from G.E., and after about a half hour of reassembly, I was able to plug the oven into a heavy duty extension cord and start it up on the bench. I wiped the the oven cavity with household ammonia to remove the smoke residue as much as possible. A bit more work and it was mounted on the wall again and back in service, although it took a couple of weeks for the remaining acrid smell to fully dissipate. Magnetron tubes are very reliable and not very likely to fail in less than 10-15 years. You’ll probably get tired of the oven before the tube burns out. The high voltage transformer is the most likely thing to fail. Since the transformer has both high voltage and low voltage secondary windings, it is possible for the high voltage winding to fail, yet the low voltage section to still work and supply power to the electronic controls. The next item after the transformer is the silicon rectifier used in the high voltage DC supply for the magnetron. The filter capacitor in the high voltage section is usually bridged by a high-value “bleeder” resistor to discharge it when power is turned off. It should be safe to work on within a few minutes after power is removed from the oven, although to be sure, one should short the capacitor terminals together with a screwdriver or other insulated tool before doing any work. Unless you are equipped with proper high voltage test gear and are trained in working with high voltages, you shouldn’t work on a live magnetron circuit, as it can kill you. The reason I felt safe in tackling this job is that I’m an electronics engineer with 40 years of experience, including training in vacuum tube circuits.

Your microwave oven not working? I am sure tht many answers blame magnetron is faulty. Why, because is expensive and not worthit to fix. I fixed nearly 200 microwave ovens ( customers returns from shops) and only about 4 magnetrons need replacement, usualy in branded models. High voltage transformer is rare to get faulty ( about 2 out 200 ). Will smell burning smoke from apliance, it is from high voltage transformer. First thing, microwave oven is very danger apliance to repair due high voltage. If you do not know how to deal with electric items ask specialist. On my blog will find instructions how to fix microwave oven. The most common fault and very cheap to fix is microwave oven high voltage fuse. This part is attached to tranformer in black or white plastick tube. Need carefully open this tube using flat screw driver. Will see glass fuse, clearly will show you if is ok or need replacement. If you replace this plart, before try apliance if working is got to check high voltage diode and capacitor. If one of this parts faulty, your new fuse will burn again in seconds. Door switches are for safety, have nothing to do with warming food.

I have a GE Profile and everything worked but it would not heat. If this is the case with your microwave then here is what I suggest. Open up your oven by removing the top cover. Let it sit UNPLUGGED for 30 minutes or better yet you MUST discharge the HIGH VOLTAGE CAPICATOR. The capacitor has enough voltage to kill you. If you do not know what a capacitor is or how to discharge it look for a video on UTUBE. Then do the following:

  1. Locate the transformer. Take of the two leads usually a red wire and a white wire and take them off. Note their locations for reattachment.
  2. Take a digital multimeter with the red lead and place it into 500V and the black lead into COM. Place the rotating switch on 200V.
  3. Take the red and black leads and place one lead into each of the transformer wires. Place the red lead into the red wire and black lead into the white wire.
  4. Plug in the microwave oven.
  5. Start the microwave.
  6. Turn on the Multimeter and read the voltage.
  7. If the voltage is 118 to 125 then then your front panel is working correctly. Unplug the unit and let it sit for 30 minutes to discharge the capacitor or discharge it. This leaves only four possible problems. It is either the transformer, the capacitor, the diode or the magnetron.
  8. my case I did not test the transformer or capacitor because they rarely go bad and the test equipment is about $150.
  9. So I just bought the diode, about $10, and replaced it.
  10. I also bought a magnetron for $102 and replaced it. Again look for video on UTUBE if you are unsure of what a diode and magnetron look like and how to replace them.
  11. Reassemble, plug it in and test for two minutes on high with a cup of water. After I did these things the unit worked like new. Hope this helps and good luck.

I fix microwaves for a living, they store over 4 thousand volts in the high voltage section, and if you don’t know what you are doing, don’t take the cover off.Yours could be one of several problems, if it programs and goes through all the motions but no heat,then you have some type of high voltage problem, that could be a bad high voltage transformer,capacitor,magnetron on rectifier.take it too a pro or have a pro come to your house.good luck

Switch contacts in the latching mechanisms can fail or become intermittent. Printed circuit boards behind touch pads can flex causing printed circuits to develop cracks over time, resulting in the same type of failures. These include no heating or ventilation fan or intermittent operation, running with door open, etc. Hard to find or fix sometimes, usually it’s poor design.

I was electrocuted when I was younger, they said I was clinicly dead for 45 min before they brought me back, and I literally did not fully wake up until the middle of the next week! The smell of burnt human flesh, and the excruciating pain should be more than enough to reason to stay away from high voltage unless you are properly trained in it. I still work with electronics and electricity but mostly low voltage projects.

I understand, no power at all. Check the fuse in plug (in UK we have), check the fuse in the microwave oven, placed above fan. If find blown fuse, check appliance for short circuits. Working with microwave oven is dangerous.

There is high voltage fuse between transformer and magnetron. Fuse can be fitted on transformer in black tube, or next to the transformer in white tube. Fuse required 750mA - 900mA5kV, mA depends on power of microwave oven. First thing to check if microwave oven not warming up food. Failed rectifier will cause to burn main fuse. http://bargains-zone.co.uk/en/small-elec…

Take it to professional don’t attempt yourself you can get seriously injured or worse.

i’m a general fix it (computer and sort of general handy) guy my microwave stopped working no power no nothing i looked up on the we bthe most is $3.00 fuse i don’t mind buying a $3.00 fuse if it’s going to fix the 100.00 microwave otherwise that’s it’s far i’m gonna go otherwise i’ll just buy another not worth the electrocution.

Have had this happen to my microwave. What I found was the door switch is not actuating correctly. When it happens, if I pull up a little on the door, while the door is closed, it runs correctly. My micro is around 11 years old.

Try to heat with different temperature means change heating temperature after some gap. Its works for me.

I slammed the door shut instead of just shutting it. Then it worked.

hello iam not sure but it could be you need a new pad.. that is not worth to fix it is better to scrap the oven and buy a new 1 on amazon,.

M y microwave don’t heat water touch. Pad light up the turntable turn but won’t heat the water it is a ge model # jmv7195sk3ss

The most common problem is high voltage fuse placed nearby or on the high voltage transformer.