good morning, i have been working on a few microwaves and i have this one kenmore 66339 model i believe. starts running when you plug it in, stop button wont shut it down, just opening the door. but once you close the door, it just starts running again. any idea what part is causeing this to happen. thank you for your time, Dave

I found that the door wasn't hitting one of the door switches when closed unless I pushed down on the door. Yours, that switch may not be working at all or could be stuck sense you said it runs open or closed.