Microwave seems to run ok, but doesn't cook

The microwave oven of the the GE double built-in unit was accidentally run on power level 10 for 40 minutes without anything in the oven. Now unit comes on (fan works, light works, control panel seems normal) but does not heat food/liquid. Blown fuse, or pull the thing out and start troubleshooting magnetron and related parts? If I have to pull the monster out, can the M-wave be pulled separate from the lower convection oven?:eek: Thanks for the help!