Once I tried to warm up some food in a microwave oven at work and it would not run (no light or fan.) I opened the door and now the fan was running. Close the d

Once I tried to warm up some food in a microwave oven at work and it would not run (no light or fan.) I opened the door and now the fan was running. Close the door and it stopped again. No idea if there was any microwave radiation coming out but I quickly unplugged that thing and put a note on it for facility staff. Not sure how a safety sensor would fail in that manner!