[GeoDoc]

I had a similar problem on my last motor home. A side opening door has two switches. One controls the fan, lights, controls and the other one controls the magnetron. When the two switches are not triggered at exactly the same time it assumes you have opened the door with the magnetron still operating. In my case works for a couple of minutes and apparently the heat generated is causing the magnetron switch to turn it off. Everything else is still working but it is no longer cooking. After cooling for a few minutes you can get a couple more minutes of cooking. With these cheap microwaves the problem can also be caused by pulling down on the door when you open it causing the door to warp, thus throwing the synchronization off.

I found the size in my manual and am  going to try and find a replacement. I also would like a combo but I think most are bigger.

Surely no one in their right mind would hard wire a microwave????