Over the Range Microwave went dead while exhaust fan only was running. No power at all going to unit. Control board has no function working or showing signs of power. In the inside of the computer control panel there is a wiring diagram, and based on the wiring and testing criteria; the thermal fuse, capacitor, diode, fan motor, and on the transformer, the primary and filament wiring test ok. I didn't test the secondary wiring of the transformer, as it is covered with a tape protective covering.

There is a MGT THERMAL FUSE shown in the wiring diagram, but I can't find it. Could that be the issue?

The secondary switch didn't doesn't appear to make contact with the door, so I held the switch down, and still no power to the unit. This might be an auxillary problem.

Is it possible that the $175 control board is dead? How do I test it for sure?

Any other ideas?

This one has been a learning experience for me, as this isn't my cup of tea. This board has been very helpful, and I hope someone can help me.

I was cooking Oatmeal this morning. after 20 seconds, the 6 year old GE emo3000cbb lost all power. The is still power at the plug. any Ideas?
signed,
cold oatmeal

In my post, it incorrectly states that I checked the thermal fuse. I checked the line fuse, and it shows continuity. From the plug to just before the line fuse where it connects to the case reads 120V.

Any other ideas???

TM

thanks Gene, it was the fuse. What causes this?