JES1288SH01 General Electric Microwave

Continuity checks showed the flame sensor was open. Schematic notes it opens at 217 degrees and closes at 30 degrees. Removed sensor and placed in freezer for twenty minutes. Tested sensor and it was now closed, reinstalled and microwave worked normally. Ordered new sensor in case the original is operating at too low a temperature.

I took the cover off and followed the electric current to see if it got as far as the display.
I did not get past the thermostat shut off where the current stoped. I jumped the thermostat and the unit worked. The part was so inexpensive that I decided to replace it rather than try and freeze the old one in hopes of "reseting" it.

Door microswith was stuck on. This is caused, I discovered, by frequently stopping the oven, while running, by opening the door rather than using the stop button. Causes the switch to arc and eventually fail. This causes the safety microswitch to trip the breaker when door is opened. There are little nubs sticking up on the spade connecto ... Read more rs. You must squeeze them down before you can remove them from the switch. The main door switch is the upper one, mounted at an angle. You have to remove the latch assembly to remove the switch. The problem was obvious once I got the switch out. This problem could also blow the fuse, but in my case the breaker tripped first. Use an ohmmeter to check switch and fuse. The door switch is normally open. The safety switch is normally CLOSED. Instructions inside were helpful and described this problem. So, avoid this repair by always stopping oven with stop button!