[masterdrago]

I've spent years as a service guy working on microwaves. What others said. Get a new unit. They are cheap today. It does not have to be a door switch issue, which would be the lowest cost fix. There are many other things that could be wrong - a slight short in the big capacitor or magnetron. Not worth spending the time and parts on. You would need to get it on the table uncovered to really check it out. Plus have the knowledge to do so in a safe manner. Like Bob and Rsmarlow82 said... replace the unit.