How to fix magnetron in microwave - GE Ovens

The timer that runs the mag is stuck. Unplug fan for 30 seconds and check it out. If not fixed, then look at replacing if microwave is older 7-8 years old.

Hi.

The wave emitting part inside the microwave oven is called the magnetron. The waves emitted by the magnetron generate heat in food. When the microwave is running, turntable turns and light comes on but there is no heat it means that either the magnetron is faulty or the magnetron is not getting power. When the magnetron is not getting power parts such as the high voltage diode or capacitor must be tested or replaced. Testing and repair must be carried by a technician. Here some general troubleshooting: http://www.fixya.com/support/r2096491-microwave_works_normally_but_not_heat

Regards.

Ginko

If there is no heating please do not switch on unless you have confirmed the fault. It is possible that the Magnetron is faulty, the temperature cut off is faulty or the main capacitor is short. It is also quite possible that insect can get into the oven and create soft spots. When you switch on these will create a short and make the voltage jump and in the long run damage the magnetron.
So Remove cover after disconnecting , check for dirt/moisture in the cabin, if so wipe clean and dry, check the magnetron and area clean and use an jet air to clean off. Check the wave guide covers, if food had deposited
then it must be checked or replaced.

See link: http://www.espares.co.uk/advice/microwave/a/5/1146/how-to-replace-a-microwave-guide-cover.html

Now keeping clear of the microwave, switch on, use a cup of water inside to test.
If you notice any sparks shut off as the magnetron or the main HT capacitor can be faulty. replace with same type.
If there is heating without any issues, you can use the microwave safely

If there is no heating please do not switch on unless you have confirmed the fault. It is possible that the Magnetron is faulty, the temperature cut off is faulty or the main capacitor is short. It is also quite possible that insect can get into the oven and create soft spots. When you switch on these will create a short and make the voltage jump and in the long run damage the magnetron.
So Remove cover after disconnecting , check for dirt/moisture in the cabin, if so wipe clean and dry, check the magnetron and area clean and use an jet air to clean off. Check the wave guide covers, if food had deposited
then it must be checked or replaced.

See link: http://www.espares.co.uk/advice/microwave/a/5/1146/how-to-replace-a-microwave-guide-cover.html

Make sure that the program controller is working if not check power - step down supply, the pads are responding- if not faulty pads- or the door switches, if contact is not through the microwave will not work.

Now keeping clear of the microwave, switch on, use a cup of water inside to test.
If you notice any sparks shut off as the magnetron or the main HT capacitor can be faulty. replace with same type.
If there is heating without any issues, you can use the microwave safely

If there is no action please do not switch on unless you have confirmed the fault. It is possible that the Magnetron is faulty, the temperature cut off is faulty or the main capacitor is short. It is also quite possible that insect can get into the oven and create soft spots. When you switch on these will create a short and make the voltage jump and in the long run damage the magnetron.
So Remove cover after disconnecting , check for dirt/moisture in the cabin, if so wipe clean and dry, check the magnetron and area clean and use an jet air to clean off.
Make sure that the program controller is working if not check power - step down supply, the pads are responding- if not faulty pads- or the door switches, if contact is not through the microwave will not work.

Now keeping clear of the microwave, switch on, use a cup of water inside to test.
If you notice any sparks shut off as the magnetron or the main HT capacitor can be faulty. replace with same type.
If there is heating without any issues, you can use the microwave safely

It is possible that your microwave has a failure in the magnetron which produces the microwave. So first of all diconnect the power ,open the cover and look inside for any damaged wires to the magnetron. There is a high voltage capacitor which can also be faulty/weak and would not assist to deliver the high voltage to the magentron.You can check the capacitor for any short. Replace if you find it suspicious with a leak or short. make sure that when you turn the microwave on without the cover, precaution of continued exposure must be avoided. make sure the relay clicks engaging the fan and table along with the magnetron if not he relay or drive from board is faulty and needs attention. So check this out. Good day

HI. Your symptoms are a strong indication Magnetron failure. This is the principal heating device, that is used to produce microwaves that , essentially, excite the water molecules in the food, thus, producing the heating effect. When this device fails, generally, the unit will run, but not heat. This device is very fragile, and can injure you if you are not qualified to handle this type of component. There is a High Voltage Capacitor, that is used to help provide the necessary current for optimal Magnetron operation. This capacitor must be discharged correctly. If not, you could risk serious injury, during the repair, if it is accidental touched.

The Magnetron is linked to a cut-off fuse. If the magnetron becomes unstable, this fuse will shut the device down. It is standard procedure to have this fuse test for continuity. If the fuse has blown, this will be the culprit. Replace the fuse. Now, if the fuse continues to show continuity, this will confirm that the Magnetron has failed. I would advise to inspect the Capacitor, and HV diode for visible burn marks, or swollen top(Cap).

Access can be ac hived to these parts by removing the outside cabinet screws. Once the screws are removed, the cover can be removed, as well. Once the cover is removed, the internal components will be exposed for testing, and visual inspections.

WARNING: IF YOU ARE NOT A QUALIFIED SERVICE TECH, THIS WILL NOT BE A NOVICE DO IT YOURSELF JOB. MICROWAVES ARE VERY DANGEROUS, AND CAN CAUSE SERIOUS INJURY. I RECOMMEND TO CALL FOR SERVICE, IF YOU ARE UNCOMFORTABLE WITH HANDLING THE CAPACITOR, OR MAGNETRON..../

Sounds like the magnetron has failed. There are some high voltage circuits that feed the magnetron and you can potentially get hurt if you don't know what you are doing. Would recommend you have it serviced by a professional if you want it fixed, otherwise look for a new one since the cost of repair can come close to the price of a new microwave oven.

Sounds like a bad magnetron (the device that produces the microwaves) - if the microwave is over 6-8 years old, it's usually not worth fixing.