Chosen Solution
Microwave started, then a loud bang and it stopped. Will not restart. Circuit breaker OK
First call your life insurance agent and make sure your policy is up to date. Next call some high school drop out that repairs these killers. Use your iPhone or iPad to tape the action for uTube. Then go buy a new one.
Normally most microwaves have a internal fuse on the circuit board thats sits on top of the fan This normally blows for a reason The most common 1 I remember is the lightbulb blows taking out fuse A loud bang is not a good thing it is normally a component destroying itself With a electricial short