Depending on your level of experience, I would only recommend checking the fuses. There is usually at least one inside the microwave itself. If you are to go looking for this fuse, be sure to disconnect the mains supply AND wait a few minutes before opening the case. The primary component of a microwave (the magnetron) uses a high voltage supply and this voltage can remain across a capacitor for a while after the supply is removed. Waiting a minute or two will allow this voltage to discharge. But be carefully where you touch. The fuse should be situated very close to where the mains supply enters the microwave case. Test it with a ohm meter to see it is a short circuit.
Good luck.
Aaron, October 2008
