The other night my wife was warming up something for dinner, she set the time and hit the start button. The microwave powered on for 2-3 seconds, made a pop noise followed by sparks coming out from underneath the unit. This is a electric oven/microwave overhead setup. The microwave would not turn back on, I checked the breaker to the oven/microwave and it was not tripped and the oven still operates.

I would prefer not to change the unit out, I didn't know if there was a fuse or maybe something simple to replace or check. Any help would be appreciated, thanks in advance!