Information on replacing Sharp Microwave fuses is available on eHow. An instructional repair video is also available on the fuse replacement part page of RepairClinic.com.
Microwave transformers are capable of discharging electrical charges even when the microwave is unplugged. Individuals should always unplug the unit before doing any work and avoid the clearly marked transformer during repairs. The fuse is located either in the back of the oven near the entry point of the electrical cord or attached to the control panel. Most repairs can be done using a Phillips screwdriver, but some models of Sharp microwaves require a Torx Security bit to unscrew the covers.