I had the lawn mower hanging from a chain while I was welding up the cracks in the frame. It caught on fire, melted the seat and a lot of the wires while I still had the hood down. Lesson learned, never enlist the help of a fire watch that has the attention span of a gnat. He went to get another beer while I was between rods.
With a lot of tape and a old pillow, I managed to get two more seasons out of that old mower. It is dead now. Just another relic in the junk pile waiting on a spark of ambition, to be reborn as another great invention, that most likely, will go back to the scrap pile.
No clue about what to do with a crapped out microwave oven, other than to deal with it much like Mr. Fix It did.