Sounds a bit like an overheat situation. If the fan really is 120V and not
speed controlled then I'd be looking for burnt wiring in the AC input
system.

However, I have a Panasonic doing much the same things. Pulled it apart
and
found the main MOV across the AC line was shooting flames out of the top!
Then I noticed that the main power transistor (this is a inverter machine)
has a big crack through the body. Only uWave I ever bought that failed on
me.

N



First thing I'd check is the fan motor itself, some hair or gunked up grease
in the bearings could be making it run slow which overheats the magnetron.