Microwaves are common household appliances. However, if you're not careful, you could damage your microwave. For example, running a microwave with nothing inside it can cause it to overheat. Microwaves can be challenging to repair because most individuals do not understand how they work. However, they can sometimes be easy to repair if you know where to start. First, make sure that the microwave is plugged in. If this isn't the issue, there are several other possible causes.