I have a multimeter so I was able to check the fuse per website recommendations and it was blown. However, the capacitor on the microwave was also original so I elected to replace the capacitor, fuse, and the ground protect diode. The repair was very simple (making sure the capacitor was discharged before replacing) and the microwave is now up and running again. Excellent trade to buy $40 worth of parts rather than a new $400 microwave. One nit - Kenmore puts a screw in the back that requires a special screwdriver head to get it out, probably to keep people from taking the cover off the microwave and working on it. I used locking pliers to grab the head of the screw and twist it out. When I put the microwave back together again, I used a normal screw so I wouldn't have to mess with that special screw again.