How to Repair Your Microwave

Fixing Microwave Oven
Eric Audras / Getty
Project Overview
  • Working Time: 20 - 40 mins
  • Total Time: 20 - 40 mins
  • Skill Level: Beginner

If your microwave stopped working–or is not working as it should–you may be pleased to learn that many problems you encounter can be fixed by you. The tools needed are basic ones you may already own, such as flathead and Phillips head screwdrivers. Even many of the microwave parts are easily available online and are inexpensive.

Working on a microwave can be dangerous. While most electrical devices immediately dispel their electricity after they have been unplugged, there is the chance that the microwave may still have live electrical parts. The U.S. Consumer Product Safety Commission (CPSC) notes that, on average, two people die per year while working on their microwaves. 

The high voltage capacitor within microwaves does retain a charge, but an internal resistor is designed to automatically empty out that charge. After unplugging, let the oven sit for at least ten minutes to make sure the charge is fully dispelled in the event of a non-functional resistor.

If you feel uncomfortable at all with this repair, call in an electrician for everything leading between the service panel and the kitchen outlet. For matters leading from the outlet to the microwave, call in a microwave technician.

What You'll Need

Equipment / Tools

  • Flat-head screwdriver
  • Phillips head screwdriver
  • Voltage detector

Materials

Which of the following supplies you need depends upon what you find through troubleshooting.

  • New fuse
  • New coupler
  • New motor

Instructions

When Your Microwave Oven Outlet Isn't Receiving Power

In this case, the microwave display will not light up. When you try to turn on the microwave, nothing happens.

  1. Check the GFCI Outlet

    According to the electrical code, outlets over kitchen counters are required to be ground-fault current interrupter style. GFCI outlets frequently trip. Unplug the microwave, press the "Reset" button on the GFCI outlet, plug in and try again.

  2. Test Other Outlets

    Your microwave may not be plugged into a GFCI-style outlet but it might still be receiving GFCI protection from another outlet that is GFCI-style. While not a common practice, this does adhere to electrical code in many communities. Unplug the oven, reset all other GFCI style outlets in the kitchen, plug in and see if the display lights up.

  3. Flip the Circuit Breaker

    The circuit breaker on the electrical service panel may have flipped off. Locate the service panel, then locate the breaker that correlates to the microwave's outlet. Flip the breaker off and then on again. 

  4. Test the Microwave Oven Cord

    You can double-check that power is running to both the GFCI outlet and into the microwave's power cord with an inexpensive voltage detector. Touch the detector to the power cord. If it beeps or lights up (depending on the tester), this means that the cord is electrified.

When the Outlet Has Electricity But the Oven Isn't Powered

In this case, you have determined that your microwave has live power running to it, but the display does not light up and the oven will not turn on.

The problem may be a blown fuse. To purchase the correct fuse, consult your owner's manual. Microwave fuses are inexpensive and readily available online.

  1. Locate the Fuse

    Access the working area of your microwave. If you have a countertop microwave, you will likely access it in the back by unfastening the metal cover. If this is a permanent, over-the-range model, you may be able to access the inside from the front.

    Once inside, you will see two black wires connected to each other with a plastic casing between them. The fuse is located within this casing.

  2. Remove the Fuse

    Open the casing with a flat-head screwdriver and pull the fuse free from the two wires.

  3. Install and Test the New Fuse

    Remove the new fuse from its package, taking care not to touch the conductive metal ends with your fingers. Touch only the center area.

    Push the fuse into place between the two wires and snap the casing shut.

    Close the access door and try the microwave.

When the Microwave Carousel Seems to Be Malfunctioning

Your microwave fully powers up and runs, but the turntable or carousel that is supposed to rotate the food spins in jerks or does not spin at all.

The issue may be with the carousel drive bushing coupler. The coupler is the 3- or 4-pronged plastic part that engages with the carousel to make it turn.

It may not be engaging with the carousel (in which case, all you need to do is align the teeth) or it is so embedded with food and other gunk that it no longer adequately engages with the carousel teeth. 

On the other hand, the issue might be with the motor. It might need replacement. While this fix may sound intimidating and expensive, it is neither. Microwave carousel motors, available online, are relatively cheap, small, and easy to replace.

  1. Clean the Carousel

    Open the door and remove the turntable by lifting it up. Grasp the coupler with your fingers (not pliers) and pull it straight up.

    Clean this item in warm, soapy water, replace it and the carousel, and try again.

    If this does not work, remove the coupler again. The coupler may be stripped at the bottom so that the motor's metal shaft does not engage with the coupler. Purchase a new coupler online and replace it.

  2. Inspect and Clean the Carousel Ring

    A plastic wheeled ring surrounds the bushing coupler mentioned above and supports the turntable. Check to make sure that the wheels on this ring easily turn. If not, immerse in warm soapy water, clean, replace, then try running the oven again.

  3. Replace the Carousel Motor

    Turn the microwave on its side (for over-the-range ovens, you can access from the bottom) and remove the access panel with a Phillips head screwdriver

    Before setting the access panel aside, you may need to disconnect a wire harness that attaches to the light. To do this, squeeze each side of the connector until the wires separate.

    Two wires connect to the motor. Slide those wires off of the motor terminals.

    Unscrew the current motor from the microwave with the Phillips head screwdriver and remove.

    Place the new motor on the bottom of the microwave. Ensure that the flat side of the motor's shaft aligns with the flat receiving hole in the coupler. Screw the motor into place, and attach the wires to the terminals.

    Restore the access panel, plug in and try the microwave.