Stove is about 2 years old. Fan will only work on low and clean. Can not get stove to work on anything except low. Replaced fan motor, 2 sensors, boards twice. Local techniian is very capable and concerned, but can't find the problem. He has disassembled the entire stove and can't find the problem. I believe the next step is to temprarily replace ours with a used one he has on hand while he takes ours away and troubleshoots it. I believe all reasonable problem reslution is being done. This is baffling. Has anyone ever seen something like this? Thanks