Microwave Doesn’t Turn On

Some of our customers have encountered the situation when they enter the kitchen and try to warm up their breakfast, only to find out the microwave wouldn’t turn on at all. They press some several buttons, try to unplug and plug it back – but if they do not manage to find out the problem immediately a lot of people come to the conclusion their microwave is broken for good and simply stop at this point. However, most of the time this assumption is frankly speaking rather preliminary. While it could be indeed a problem with a crucial component such as magnetron, the average home appliance is in general sturdier than that. There may be numerous reasons why your microwave wouldn’t turn on, and we will examine several of them in this article. Keep in mind that some of these problems are rather basic and easy to repair. However, please keep into account that microwaves use a high voltage circuit, which is dangerous to operate. Make sure to always unplug your appliance before you attempt any repair!

Faulty Door Switch

The microwaves are designed the way that the opening of the microwave door will shut off the appliance immediately. It could be that the problem with your appliance lies in the broken interlock door switch. Sometimes, if your door switch is broken the control panel and the lights of the microwave might be on and seemingly working, but the microwave wouldn’t start heating up anyway.
Unplug the microwave and remove the cabinet. The interlock switches will have wires attached, marked as C and NO. Check the switches for continuity using the multimeter. Press the actuator manually – you should be able to detect continuity between the terminals. In case there is no continuity, the switch has to be replaced.
Examine the door hooks and make sure they are not broken and they properly engage the actuator once the door is closed.

Broken Fuse

Ceramic fuses are microwave components, which protect the circuitry from the power fluctuations. Sometimes, a blown fuse may indicate a bigger problem with your microwave, but most of the time replacing the fuse will allow you to use your microwave again. Make sure to unplug your appliance before conducting the diagnostics! The ceramic fuse is located inside the cabinet, close to the power cord. Check the fuse for continuity with the multimeter. If the fuse has failed when you opened the door – check the door components for continuity, makes sure they are properly wired and not shorted. Otherwise, it may make sense to check the magnetron and the high voltage circuit as well. Keep in mind that this diagnostics should be conducted only if you have adequate experience in working with high-voltage electrical components.

Faulty Thermal Cut Out

This component is responsible for turning off your appliance whenever the microwave overheats. A faulty component might prevent your microwave from turning on. Locate the thermal cut out (sometimes called a thermal fuse) in the user manual. Make sure to unplug your appliance and take off the cabinet. Disconnect the wires from the terminals and test the cut outs for continuity. You may have to replace the component if it has no continuity. Have a look at your cooling fan as well. If your microwave oven starts working but then turns off after a while your cooling fan might require cleaning or more careful diagnostics.