Microwave door switch. This switch is normally open. When the microwave door is shut, the door switches close to send power to the microwave. If this switch fails, the microwave will not start.
Microwave diode assembly
Microwave/range thermal fuse. If the appliance overheats, the thermal fuse blows to cut off power to the appliance. If the thermal fuse has blown, the appliance will no longer heat.
High voltage transformer