How to Fix a Microwave That Will Not Turn On

There are many reasons your microwave won’t turn on, one of which might be a faulty door switch. The door switch, also known as an interlock switch, signals other microwave components to begin powering when the door is closed, and to stop when the door opens. For this reason, everything else may appear in working order but the microwave will not begin heating.

How to test a microwave door switch with a multimeter:

1. As you will be testing electrical components, verify that you have unplugged your microwave before beginning.
2. Locate and remove the door switch. You will need to remove the cabinet in order to access it. You should also inspect the door hooks that trigger the door switch to verify they are activating the switch mechanically
3. To test the switch for continuity, set your multimeter to Rx1, depress the actuator button and touch the terminals with the probes. You should receive a reading of 0, indicating that there is continuity.
4. If your switch does not have continuity between the terminals, you will need a replacement door switch.

Your microwave may not start because of an issue with the door latch assembly. Most door latch assemblies are made of plastic hooks that stick out of the door and engage the door switch when the door is closed, signaling the rest of the controls to power the microwave.

How to inspect a microwave door latch assembly:

1. As with most microwave inspections, begin by unplugging your appliance.
2. The door latch assembly will be found attached to the door; you will need to remove the inner door panel in order to access it. To inspect it closely, remove it from the appliance.
3. Looking for any signs of wear, discoloration, damage, or cracking, visually inspect the door latch assembly.
4. If you find any issues while inspecting it, you will need a replacement door latch assembly.