Have GE spacemaker XL. When running, it seems

If it was run without the fan a thermal protect device was more than likely taken out. Check for that and replace the fan.

either the magnatron fried , or the fuse fried... either way the microwve has to be taken down and opened up.
If you have the serial number , GE will send you a replacement magnatron (but will not service the unit for you).
contact GE and they will take care of you... the magnatrons are warranted for like 10 years....

https://www.manualslib.com/products/Ge-Jvm3670wf-Profile-Spacemaker-Xl-1800-36-Microwave-Oven-1842926.html

Click link to download manual

You likely need to replace the fan motor.

We see (and repair) this a lot. The problem is on the control panel, which we regularly repair nationwide by mail for $39.95 postpaid in about a week or so.

This light failure often occurs when a bulb goes out and the filament shorts, or when the bulbs are removed or installed without first unplugging the oven from the power line. Either can cause such a failure on the controller.

This can often also affect the exhaust fan, cooling fan, turntable, and/or inside light operation, too.

Details of our service are at our Web site, along with a video showing how to remove a typical over the range control panel assembly in under 5 minutes.

Feel free to contact me directly with your brand, full model number and symptoms.

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 noise you are hearing is due to the fan. The fan is used to cool the magnetron during cooking, and because this fan is not working the magnetron is overheating and the thermal protector is opening, killing power to the unit. All you need to fix this is a new fan blade. The fan blade(look for part #80) is slipping on the motor shaft ( the noise you are hearing).

GE XL 1800

If the blade is broken then you can buy a new one from---

GE FAN BLADE

Please ask for further clarifications.

A Fixya rating would be appreciated if you find it useful.

Thanks
Rylee

Assuming that your internal cooling fan is working, I would suspect that your magnetron is failing.

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

There should also 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, and locating components.

I would check the cooling fan, then suspect the magnetron.

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

model # JVM1870BF001 GE Profile spacemaker XL 1800 microwave

after episode of using defrost which burned food--now stopped heating--still has power/fan--don't know how to change fuse--please help

SOME BUT NOT ALL OVENS HAVE RELAYS TO TURN THINGS ON AND OFF CHECK THE OVEN TO SEE IF YOU HAVE ANY
RELAYS AND SEE WHAT THEY DO.

Sounds like the problem is in the high voltage. Most common would be magnatron, capacitor and diode. For safety reasons this should be checked by a professional. Look in your owners manual because some high voltage parts have a longer warranty than 1 yr.