GE Spacemaker No Heat When Exhause Fan is Running

[tfratzke]

First time post.
Microwave stopped working last week. Problem originally was microwave would run for about 2 seconds until the magnetron would try to kick in and then it would shut off and reset.  Main computer Board was replaced. Didn't fix the problem.

Next i replaced the magnetron. All seemed well and working normal until i noticed something odd tonight. If i am running the exhaust fan, the microwave does not heat. You can tell too because the magnetron never kicks in.  Turn off the the exhaust fan, viola, works fine.

I can repeat this crazy pattern every time. I ordered a new diode tonight as i have not replaced that yet. I found out later it was suggested to do that at the time of magnetron replacement.

Any ideas of what it may be? Any help is appreciated!

Thanks!

Model JVM2070WH001

[tfratzke]

I kinda figured this conundrum i have would be an odd one for everyone.

Do you think there is a slight chance replacing the diode will fix this? The only thing i can think of is that there simply isn't enough power for the magnetron to operate when the exhaust fan is running. To me that points towards something being wrong with either the diode or maybe even the capacitor?

I do have the old control board so i am going to put that back in this evening, (since it wasn't bad) to eliminate this issue being related to the control board.

Thanks,

[JWWebster]

Maybe you need to get an electrician to bust the wall receptacle using a special breaker like that which is used for dishwasher and disposals. Must be a heck of a vent motor.

[tgoods]

It's an odd problem.  Sounds like it might be pulling neutral through the blower motor.  If you're sure you reconnected all wires correctly, check your switches and relays.

[tfratzke]

Just thought i would update for people who are interested.

The issue was the new board from GE was faulty. When i put the old working board back in, everything works normal. To be sure, i put the new board back in again, and once again could replicate the problem.

Thanks for the input!

[tgoods]

Thanks for the update. It's always fun to solve the weird ones.

[JWWebster]

I would have replaced the mag first before the board. Glad you figured it out.