What Causes A Microwave To Suddenly Stop Working

Your microwave is working fine. You put in a meal to heat it up, but the oven doesn’t work. What should you do? First thing you need to do is find the cause of the problem yourself or by hiring an appliance repair technician who will professionally inspect and fix it. If you want to find the problem yourself, give this guide a read.

Blown Main Fuse

Most common cause of a microwave not working is a blown main fuse. A replacement of the fuse will fix the problem. But before replacing, take out the fuse and check it if it’s faulty by using a voltmeter or a resister tester.

With a resistance tester, if it shows the value as infinity then the fuse is blown and should be replaced. For testing with a multimeter, if the fuse doesn’t show continuity, it is broken.

How a fuse is blown? Most of the time due high voltage or overheating. When the microwave experiences high voltage of current, the fuse cuts the flow of electricity to save the main components of the oven. This results in a blown main fuse.

Blown Thermal Fuse Or Others

There are also other fuses in an oven such as thermal fuses, thermoprotectors, and cavity fuses. If the main fuse is fine, check these fuses one by one with a multimeter and find the fuse which is faulty. There could also be multiple blown fuses, so check all of them as a precautionary measure even when you have found one blown fuse.

Defective Door Switch

Oven door switches are responsible to start or stop the heating process once the door is closed. Usually, you will find three or four switches in an oven. Test them one by one. When one or more door switches are not working, they won’t let the oven start the heating process even when the door is closed because they can’t detect it. You can also check door switches for continuity with a multimeter.

Moreover, if you have one or more faulty door switches, you must check the main fuse because broken door switches cause the main fuse to blow.

Fault In The Main Control Board

It’s rare in microwaves, but a few times, the main board of the oven is responsible for the issue of your oven not working at all. But before inspecting the main control board, check the above parts to find the issue. If you don’t find any problem in them, then check the main board. There are replacements available for every oven component and you can buy them by showing your oven model number.


Microwave ovens are electric and although everyone plugs it off before opening or inspecting it, there is a hazard. It is due to high voltage capacitors which are used in microwave ovens. They retain the charge even when the appliance is plugged off. It is recommended to try oven troubleshooting when you have experience handling electric appliances.

How To Discharge A High Voltage Capacitor?

Find the capacitor which is at the lower corner of the back side of the oven. Now place a screwdriver or any similar tool on each set of the capacitor terminals to discharge the oven capacitor. Be sure to avoid touching the blade during the process.

The Need Of An Expert

We have provided the method of discharging a capacitor but there is danger of electrocution if it’s not followed properly. Therefore, hiring an appliance repairman is recommended.

For selecting a repair service, firstly, ask around your neighbor, family, colleagues, and friends. When they suggest a name, check that company’s certifications or proof of training.

After this, the most important part is discussing the cost of repair. Some repairmen will have to check the appliance for giving you an exact service charges along with the cost of the replacement parts. It’s smart to get quotes from different companies and compare the pricing.

Lastly, ask your oven repair Springfield company about the warranty of their service because you wouldn’t want the oven to break down only a week after the repair and then paying money for its repair again. Some services provide warranty while some don’t. You can simply choose the repairman who provides a warranty.

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