A year or so ago my microwave stopped heating. Everything else worked fine. I looked some stuff up and thought that it was probably the magnetron. I called and had a GE service guy come out. I wasn't home to watch what he did but my wife said that she thought that was what he replaced. I can't find the service order now. He said it was because we cook popcorn in there that it went out. Anyway, now it's doing it again. No heating. Does that sound like the magnetron, and is it easy for me to just get the part and replace it myself. Is there a service manual out there somewhere?

After reading about the possible repairs and realizing how much it will cost even for parts, I've decided to just buy a new one. The problem is, mine was a 2.1 cubic foot and now they are all 2.0 cubic feet, and 1/4 inch shorter, so I'm wondering if it will look ok in my existing GE built in trim kit and if the screw holes will match up on the new microwave. I'm hoping that all of the countertop GE's in that general size have the same mounting holes for the trim kit. If not, I guess I will be making new ones. I'm thinking that an extra 1/8" on both the top and the bottom won't look too bad.