Microwave doesn't heat, plate doesn't turn

We are very sorry to hear this and we apologize for the inconvenience this has caused you. We would be glad to look into this if you could email us at [email protected] with your name, address, phone number and the model & serial numbers of the Microwave.

You may have a shorted door switch or a shorted relay on the control board.

You can see a help file on door switches here.

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

see the next causes. God bless you
Diode The high voltage diode converts the A/C power output of the transformer to D/C, doubling the voltage to nearly 5,000 volts. This high voltage powers the magnetron which emits the energy that cooks the food. If the diode burns out, a lower A/C voltage reaches the magnetron, which is not sufficient to power the magnetron. When the diode fails it is often visibly burned out. If it appears to be good, it can be tested with a volt-Ohm meter capable of testing diodes. High voltage diodes frequently fail and are one of the most common points of failure in a microwave oven.

Door Switch If the microwave does not heat, one of the door switches might be defective. Microwave ovens normally have three door switches, if any of them fail the microwave does not turn on and does not heat. Check the switches for continuity with an Ohm meter.

Magnetron If the microwave oven doesn't heat the magnetron tube might have burned out. The magnetron uses high voltage, high current DC power to generate the microwave frequency that cooks the food. If the microwave oven is turned on when it is empty this can cause the magnetron to burn out. Once it is burned out it has to be replaced, it's not repairable.

High Voltage Capacitor If the microwave doesn't heat the high voltage capacitor might be defective. The high voltage capacitor works with the high voltage diode to convert the output of the transformer to DC voltage and to double the output voltage. If the capacitor is burned out the entire high voltage circuit stops working properly. The high voltage capacitor can be checked with a special VOM meter which has a capacitance testing capability. Be aware that the high voltage capacitor can retain a charge of more than 3,000 volts and can injure or kill a person if not handled properly. Only trained technicians should perform this type of testing.

High Voltage Transformer If the microwave does not heat, the high voltage transformer might be burned out. Microwave ovens produce a very high voltage in order to power the magnetron antenna, which emits the energy that cooks the food.

Thermal Fuse If the microwave doesn't heat the thermal fuse may have blown. It can be tested for continuity. Watch our fuse testing video for more information.

Thermoprotector If the microwave doesn't heat the thermoprotector may have tripped. This is a safety device to prevent the microwave from overheating. It can be tested for continuity to see if it's blown.

Main Control Board If the microwave doesn't heat the main control board may be defective. This is not common. When a microwave doesn't heat the problem is usually within the high voltage circuit; either the high voltage capacitor, diode, transformer or magnetron.

My microwave is doing this as well; It's a frigidaire model #FGMV154CLFA.

After using the microwave part (it is also convection), the light stays on in the microwave and the turner keeps turning.

And I've only used the convection part of my microwave a couple times and I'm not sure if I was successful. While trying to cook something in convection mode, I pressed convection, then pressed the temp i wanted, then convection, then keyed in the time I wanted the item to cook. The microwave started and the timer started counting down but the countdown stopped with 8 minutes left? I left it alone to see what would happen and it never finished so I restarted the process again.

PS..I've never gotten an error code

When it times down but doesnt heat it is typically a problem with the door switches, especially one you just bought, may have been from shipping . A switch or connection may have been disodged when being shipped to you. Most machines have something like 4-5 wswitches, If 1 doesnt report right it will stiop the unit from running. But since some of them are closed it will accept the programing and try to operate. So a lot of times you get fan running and tray turning but no power to the secondary circuits. You will need to find out who does warranty for them or return it where you bought it as a defective unit.

We have a similar problem! It sounds like a problem with the microswitch inside the unit that the door is suppose to engage when closed. If not engaged properly, it will not cook. We had the switch replaced last March but it has started acting up again. We can press in on the door and/or lift it slightly and it will cook. Try putting time on the counter and hit start. It the word "cook" appears then try moving the door slightly and see if the turntable starts turning. If not, then you may have a more serious problem. Good luck!

Ok just figured this out! It is a problem with the alignment on the lower door switch. I took the cabinet off and lifted up on the door switch slightly and voila! It works. You could probably fix this without taking it apart, just lift up on the door ever so slightly. I hope this works for you.

Generally, the most common causes of a failure to heat are:

- bad door switches or door switch mounts
- loose connection at the magnetron
- problem or loose conneciton on the control unit circuit board
- bad magnetron or other high voltage part

If you or a friend decide to look into it, we have critical safety information, info on door switch diagnosis and replacement, and disassembly information at our site, linked here on Fixya: http://tinyurl.com/yzjozk

Sounds like a classic bad door switch or switch holder. If you or a friend decide to work on it, we have *critical* safety info, info on door switch testing and replacement, and oven disassembly info at our site, which is linked at our listing here on FixYa: http://tinyurl.com/yzjozk You can find helpful exploded view diagrams and order parts by entering your base model number (without the suffix) here: http://tinyurl.com/gv383