Ge spacemaker XL1800 - open the door and it starts buzzing - unplug and it quits - plug back up and push any button and all it does is buzz - will not do anything else

If the magnetron was making louder noises prior then replace the magnetron. While the cabinet is open make sure to look for burned wires, check the continuity of thermal cutoffs, and check the main circuit-board for burned traces or components. The relays in most electronics are known for arcing (spot welding) and staying in the wrong position. Tap them hard with the back end of a screwdriver.
You may have to replace the capacitor too. During all of this use safe electrical practices by having the power cord unplugged. The capacitor could still have a high charge on it so be careful.

Could be the magnetron or the transformer. No it is not worth repai

If you have had trouble with the cooktop lights recently, or if you get a hum or buzz in the area of the control panel assembly when you open the door, either indicates that you need circuit board repair. More details here.

That is a control circuit board issue which we regularly repair with our $39.95 service nationwide.

Or if you prefer, you can order a new smart board / PCB assy (part number WB27X1043) from the Pros here, our favorite supplier. It runs $259.53.

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.

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

We see (and repair) this a lot. The problem is electrolytic capacitor that fails on the control circuit board, which we regularly repair nationwide by mail for $39.95 postpaid with a one-year repair guarantee.

At our Web site, you can get details of our service, plus we have a video available showing how to remove a typical over the range control panel assembly in under 5 minutes.

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

You should keep it unplugged until it's fixed. If it's cooking while it should be off, that can damage the oven or even start a fire.

It's either a failed door switch or door switch mount, or a bad electrolytic capacitor on the control board, which we can repair for $39.95.

If you're hearing a fan or motor running, I'd suspect the switch. See this file for help.

If it's a buzz (like a power line buzz) then I'd suspect the board capacitor.

Feel free to contact me directly (and please include your full model number from the tag in or on the unit) for more 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

the magnetron needs replacement my friend, although you can still heat up food but eventually it will soon fail.
appreciate your kind comment

Chances are this is a problem on the control panel. We repair these for customers nationwide with our guaranteed $39.95 service.

Please feel free to contact me directly if you need more help. And please mention your model number when you write.

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

William E. Miller, AS-EET
[email protected]
http://www.microwavedisplay.com

My microwave was totally dead. Things I discovered: 1) There is an easily replacable fuse accessed by taking off the top front vent cover (two screws on top, gently massage off) and then the inside plastic grill. UNPLUG before doing this! 2) Pop off two wires on either end of fuse holder for safety. Then pop out fuse and replace. For more extensive help, there is an evelope with a wiring diagram inside the case on the inside wall! Very helpful when diagnosing the surface lamp problem (I forgot to plug the ballast back in when I closed up the bottom).

I have a GE counter top microwave oven. When the oven starts cooking (the magnetron turns on) the oven makes a harsh buzzing noise. What is wrong and what should be done?