The 10 Most Common Microwave Repair Problems

In many households, the microwave is the single most used appliance in the kitchen. You can microwave pasta, soup, and whole dinner plates. You can make tea or instantly prep a hot breakfast. So when your microwave breaks down, it’s only natural to try your hand at repairs. For such small, affordable metal boxes, microwaves are surprisingly complex. There are many different ways that a microwave would go wrong. In fact, the list of most common microwave problems is surprisingly long on its own, and each issue has multiple possible causes. A microwave is complex under the hood and often, you will need the help of an experienced appliance technician to safely replace the tightly packed electrical components. Let’s take a look at the possible causes for the top ten microwave problems. 

1. Microwave Plate Won’t Turn

• Plate
• Guide Roller
• Coupler
• Drive Motor

The turning microwave plate is essential to evenly cook the food. your microwave plate needs to support your food while also turning steadily to cook the food evenly on every side. If your plate won’t spin, this relates to an entire spinning assembly designed for the purpose. First, check the plate. Then look at the wide guide-rollers underneath the plate. Then check to see if the pronged coupler in the microwave center is cracked. Finally, inspect the drive motor for current and coupling.  

2. Microwave Won’t Turn On

• Wall Plug
• Door Latch Assembly
• Door Switch
• Thermal Fuse
• Ceramic Fuse

Of course, your microwave is completely useless if it won’t turn on or respond to button presses. A microwave that seems to not turn on may be suffering from a number of failures. Start by checking the wall plug to ensure the microwave is plugged into power. Next, check the door switch and the door latch assembly. The microwave won’t start if the appliance believes the door is open. Next, check the two fuses, the thermal fuse, and the ceramic fuse, to see if they need to be replaced. 

3. Microwave Door Not Closing Properly

• Door Latch Assembly
• Hinges
• Torsion Springs

With older appliances, it’s common for the door to stop hanging or closing properly over time. This often happens because the hinges or springs have come loose from their original factory tightened state. When the door doesn’t close properly, heat and smells can escape the microwave while other malfunctions ensue. A microwave door that won’t latch might be difficult to open or close, and the microwave may struggle to acknowledge the door as fully closed. Consider looking closely at the door latch assembly and the hinges, along with the torsion springs related to the hinges. Tighten loose screws and replace any damaged parts. 

4. Microwave Door Stuck Closed

• Microwave Latch Assembly
• Open Door Trick

Sometimes, a microwave door can become stuck closed. This is particularly common in microwaves that have a push release door switch. If your microwave door is stuck closed, don’t worry. There is usually at least one manual override so that the microwave door can be opened without the usual button or mechanism. It helps to know what this manual door override is for your model of microwave. Once you master the open door trick, take a look at the latch assembly. This is most likely where you’ll find the stuck door problem. You may also want to repair the door handle and/or button release mechanism. 

5. Microwave Doesn’t Shut Off

• Door interlock switch
• Smart Board

Another problem can be that your microwave doesn’t stop running when the timer runs out. This alarming situation is surprisingly common and can do a lot more than overcook your meal. You may need to force the door open or unplug the unit to stop it from cooking. In this case, you want to take a look solely at electronic parts that might be at fault. The door interlock switch might not be triggering. Or the microwave’s smartboard which controls all of the microwave’s computer functions like timing how long the unit runs. 

6. Microwave Not Heating

• Door Switch
• Voltage Diode
• Magnetron

When a microwave starts to get old, it’s more likely that you will run into the problem where the microwave light comes on and it hums, but no heat is created. If your microwave is not heating, the first place to look is the door switch. Just in case the door isn’t latching and therefore the cycle isn’t starting. You can also check out the voltage diode. But if you determine that it’s the magnetron, you might as well replace your microwave. 

7. Microwave Making Noise

• Plate and Drive Motor
• Magnetron
• High Voltage Diode
• Cooling Fan

There are several different things that can cause your microwave to be noisy. The easiest thing to diagnose and fix is a noisy microwave plate. If the plate is rattling, investigate the coupler and guide roller. If it’s the drive motor or magnetron, these are among the most challenging to replace. It might also be the high voltage diode. Depending on the microwave, it might also be the cooling fan. 

8. Microwave Touchpad Does Not Respond

• Membrane Switch
• Control Board

One of the most frustrating types of microwave malfunction is when the touchpad stops responding. A microwave should at least beep when you push the buttons. If your touchpad seems to be completely dead, it could be one of two things. First, check out the membrane switch which can determine the responsiveness of each individual button. If it’s not the membrane switch, it might also be the control board that controls all responsiveness. 

9. Microwave Exhaust Fan Not Working

• Air Filter
• Grimy Moving Parts
• Exhaust Fan

For above-the-range microwaves, there may be an exhaust fan that helps keep the air clear above your stove. When the exhaust fan stops working, there are a few different things you can try. First, investigate the air filters. A charcoal or metal mesh filter can be changed out or washed and cleaned to restore them to usefulness. Sometimes, that’s all it takes to get your exhaust fan working again. Next, take apart all the moving pieces, clean them, and put them back together. And if you find a broken part in the exhaust fan assembly, replace it. 

10. Microwave Light is Out

• Lightbulb
• Control Board

Finally, there’s your microwave light. The microwave light lets you know when it’s on and helps you to keep track of the food you’re cooking. When the microwave light goes out, the ease that the bulb can be replaced depends on the model of your microwave. But you may have to fully open up the case to replace your microwave light. If you know the bulb is good, the problem might alternately be your control board.

—For more detailed instructions on how to repair or replace parts in your microwave, contact us today!