Black circle I have a 9-year old GE microwave that has recently developed a black circle (2'' dia) on the bottom. unit appears to be working though. any thoughts as to what this might be?

I'm sorry to say that it's most likely the magnetron that's shorted out (the high voltage device that produces microwaves). It's usually the case with ovens this old that a compatible replacement won't be available.

There's also the fact that your oven is likely way past it's 'end-of-life' date so even if you could find a replacement, other components will begin to fail as more time passes.

In short, save yourself the money, time, and frustration with a new unit. Good luck!

Magnetron and diode most likely. Need more info.

I just removed mine this morning and was having the same problem, though mine did have the screws above going into the unit. You may have to pop the front vent cover off to locate the screws going to the wall bracket, if so remove those. Also,there are 2 tabs on the bottom of the wall bracket that the back bottom edge of the microwave slip into, keeping the microwave from being pulled forward. Tilt the microwave slightly forward and push the bottom back edge of the microwave up to clear the tabs. Hope this helps.

I would say it is a sign of trouble.

Not to say that it's catastrophic, but on these models part can be pretty expensive.

We regularly repair such control units for customers nationwide by mail for in about a week with a one-year guarantee.

Feel free to contact me directly (and please remind me of your full model number) for more information & help.

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

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

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.

Fixed it. There was a back capacitor fuse (I believe that's what it's called) on the old magnetron. I removed it and put it on the new magnetron. The HV diode is on the big silver capacitor and very easy to replace. I just didn't see it. It was definitely the magnetron and I hope that this new one comes with a warranty for 5 more years.

Sadly, we hear of this over and over.

This is due to a defective or loose magnetron causing electrical interference and disruption in the control circuit board.

If your magnetron was recently replaced, it may have loose mounting nuts or bolts or maybe the wire mesh RF gasket was not installed or got pinched.

It may also need a new high-voltage diode and stirrer, and the cavity may be affected.

Details are in their bulletin here. Even if your model is not on the list, the same problem can occur, requiring a kit.

If it's within the magnetron portion of the warranty (usually 5-9 years) but out of the original full warranty (usually 1 year), then your manufacturer will cover the part cost, but not the cost to visit you or the labor charge to do the work.

They 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.

:-)

First of all, there seems to be a typo in that model number, but no matter.

This is usually due to a defective or loose magnetron causing electrical interference and disruption in the control circuit board.

If your magnetron was recently replaced, it may have loose mounting nuts or bolts or maybe the wire mesh RF gasket was not installed or got pinched.

You should have a 1 year part & labor warranty, plus a further 5-9 years on the magnetron itself.

GE can point you to an authorized service center. Their Customer Service is at http://www.geappliances.com/service_and_support/contact/

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

This is often due to a defective or loose magnetron causing electrical interference and disruption in the control circuit board.

If your magnetron was recently replaced, it may have loose mounting nuts or bolts or the wire mesh RF gasket was not installed or got pinched.

It may also need a new high-voltage diode and stirrer, and the cavity may be affected.

GE had a campaign (but not a recall, mind you!) covering several models.

Details are in their bulletin at http://207.234.249.73/mwd/ge_mw_mag_kit_bulletin.pdf

The parts kit (that GE used to pay for) is part # WB27X10489 and is shown in the photo here:

http://207.234.249.73/mwd/wb27x10489_ge_mag_stir_kit.jpg

If you or a friend decide to look into it, we have critical information on safety, disassembly and door switches at our site, and our link is at our listing here on FixYa: http://tinyurl.com/yzjozk

You can find helpful exploded view diagrams and order parts by entering your full model number here: http://tinyurl.com/gv383

You say this is only 2 years old? I thought these models were much older... GE may cover it, but you'll have to contact them.

GE Customer Service is at http://www.geappliances.com/service_and_support/contact/

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