My friend has a KitchenAid in-wall convective microwave over, I believe the model # is KBMC109jSS0, though I could not find it anywhere.
The microwave normally works fine but sometimes it starts beeping for no apparent reason. He has to depower it via the circuit breaker. After a few hours, sometimes the next day, he can repower it and it works fine for a while before it starts beeping again.
We replaced the main control board with a new one (the exact part #), powered it up, set the time and checked all of the functions. It seemed to do the trick until about 4 hours latter when it started to beep again.
It doesn’t look like there are many parts in there. Any ideas what else it could be?
Thanks.