The only sounds you want coming from a microwave oven are sounds of popping corn. But something is seriously wrong with yours because it's making really loud grinding noises and you don't know why. Repair Clinic can help you diagnose the problem and find the part you need. Take a look at our symptoms below. Do you think you need a new magnetron or exhaust fan motor? Or, does is it more likely you need a stirrer or turntable motor? Once you identify the problem, you can save money by ordering the parts from us. However, because microwaves can give electric shocks even when they're unplugged, you'll need to call a licensed technician for repairs involving electrical components.