Magnetron cooling fan

I suggest you have the microwave oven replaced, the prices have dropped considerably for the last several years and you have got your money worth out of the unit.

If the microwave oven is 10 years old then it is time to consider a new unit, by your description it is going into cascade failure where different parts have stopped working, the buzzing sound is the magnetron warning you, it is about to fail. The fans job is to keep the magnetron cool while it is running.

your oven shut down because the magnetron got too hot (has a resetting thermal switch) .. it needs a constant and high flow rate of cooling air .. there is a fan that blows air over the magnetron fins ... sometimes the plastic frame that holds the fan becomes warped or broken .. the fan then doesn't deliver enough air to where its needed ... the squeaking noise however may indicate that the fan blade is either hitting the frame or the bearings in the fan motor need lubricated ... the fan is most likely the problem .. you can replace it or Lube it and repair any broken mounts .. make sure the fan turns freely and is aimed correctly .. use a light machine oil (intended for very small motors) or sewing machine oil .. not wd40 or oil with teflon .. your magnetron will be damaged if it continues to overheat .. you can gain access to the fan by removing the cover but do so only with the power disconnected and taped so no one can plug it in while you are working .. when plugged in there is potentially deadly voltage and current available inside .. . there are indeed two fans .. the vent fan and the magnetron cooling fan .. the loud laboring noise often happens if the magnetron is shorted or if the high voltage diode or voltage doubler capacitor is shorted ... but since your machine is still working until it gets hot i suspect those are not he problem yet but may be eventually damaged without cooling air flow .. that model GE did have problems with the fan mount and that in turn damaged some magnetrons ... the lube in the fan bearings generally is reliable up to 5 years depending on use .so that could be the problem as well

If it's less than one year old, it would be fully covered under warranty and I'd suggest contacting GE Customer Service here to get it fixed free.

If it's the magnetron and it's outside the 1-year labor warranty, but within the 5-year magnetron warranty, the labor to replace the magnetron would probably run about $50-75, which can instead be used toward a new oven.

If you or someone you know might want to replace the magnetron, and it's within the 5-year magnetron warranty, GE will send you one free. Call them at 888-239-6832 with your model, serial, and manufacturing date.

Some info on troubleshooting:

When you hit "Start" to microwave, do the inside light, cooling fan, and turntable all come on?

If not, then you probably just have a bad door switch or door switch mount and should see these files:

http://www.microwavedisplay.com/safety.txt
http://www.microwavedisplay.com/disassembly.txt
http://www.microwavedisplay.com/doorsw.txt

If the inside light, cooling fan, and turntable are all coming on, then the problem is in the high voltage section, and then the next questions arise:

Any unusual noises? Is it louder or quieter than usual?

We have a sound clip of what a microwave should sound like when the cooling fan and high voltage section are operating here.

A loud buzz, hum, or groan is usually a shorted high voltage rectifier diode, but a sound like gurgling into an empty coffee mug is one symptom of a failed magnetron, and yet the mag can be bad without that sound.

If there's no unusual noise, it may just be a bad connection at the magnetron.

Here are some links you or someone you know can use (in order given) for high voltage section test help, but read the safety warnings first:

http://www.gallawa.com/microtech/diode.html
(if it is NOT shorted or burned looking, it's probably fine)

http://www.gallawa.com/microtech/mag_test.html
(continuity can be good even though mag is bad!)

http://www.gallawa.com/microtech/xformer.html

You can find links to helpful exploded view diagrams and part ordering help here.

I'd recommend that your bookmark this link to your favorites.

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

hi..it sounds like a magnetron problem.It might have
got into damage.
check this out..
thank u..
kindly rate my response..

I have an over the oven microwave that blew a magnetron after 4 years. Could be the same thing. It was out of warranty for the free labor, so I took it apart (I'm kind of a geek) and found out the magnetron was gone. Shortening the story: I bought a new magnetron from an online place and replaced it and it works fine. If you have someone replace your magnetron, see if you can get it for free-they have a long warranty on the magnetron ($150 part) and at 5 years, you probably qualify. Rich

Q - My microwave seems to shut off every once in a while, what might be wrong?
A - Make sure you hear the fan is still operating in your microwave. Next is to make sure the air intake grill on your microwave is not plugged up with air borne dust and dirt.
Q - The fan in my microwave oven is not running will this hurt my microwave?
A - YES, the fan cools the magnetron and electronics, take the microwave in for service, most fans are not too expensive to replace.
Q - My microwave blows the fuse inside itself as soon as I push the start button.
A - Usually a shorted high voltage capacitor...see components section.

It sounds like the magnetron overheated and opened the thermal fuse on the magnetron.

This can be caused when the internal cooling fan is not running or by a magnetron that is failing.

When I say internal cooling fan, I do not mean the hood vent exhaust fan which you can turn on and off manually.

I'm instead talking about the internal fan which comes on automatically whenever you microwave.

It is vital that the cooling fan runs, or the magnetron will be destroyed.

There should 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.

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

The magnetron will have a 5 to 9 year warranty. Your manual will tell you that.

You can download GE owner's manuals and installation instructions here.

If needed, GE may send you a replacement magnetron. GE Customer Service is here.

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

Fisrt, check to be sure your missing cat it not inside the unit. IF the interior is dirty (splatters, grease, etc.) , it may inhibit the unit from working properly.

:-)

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 It's most likely a bad high-voltage transformer or magnetron, but it's hard to say without being able to check it. If it will run without blowing the fuse, you may be able to do a test. This should only be performed by someone observing safety warnings mentioned at the link above. Put about 2 cups in a microwave-safe container inside the cavity. Run the oven for about 3 minutes, or until it blows the fuse. Then unplug the oven from the wall, and carefully feel the top of the high-voltage transformer and inside or near the finned area of the magnetron to see if either gets really hot. If one does, it's the likeliest suspect. When the high-voltage transformer fails, it often gets discolored and smokes, but not always. You can look for that, too. It's very important that the internal cooling fan is running, and that the air vents are not blocked opr plugged.