Since their creation, microwaves have always brought convenience and ease to home cooking. Owning a microwave is almost considered a necessity at this point. Everyone, from senior citizens to college students, has one. Unfortunately, microwaves were not built to last forever. Every microwave will eventually break down. But with replacement microwave parts, they can!

If your microwave is malfunctioning, consider troubleshooting the problem before throwing it away or taking it to a repairer. It is much cheaper to order the corresponding part and replace it yourself. Repairing a microwave is also much better for the environment since the electronic waste does not end up in a landfill.

The only hurdle is learning how a microwave works. Microwaves can be potentially dangerous if you go blindly tinkering in them. As such, it is crucial to understand it before replacing anything. To understand this machine, we must first learn about the specific microwave parts and how they function.

The Specific Parts of a Microwave

woman using microwave

Though there are too many different wires and circuits in every microwave to even list, here are the most important parts to know. If something is wrong with your microwave, you will likely need to replace one of these parts.

  • Triac — The triac is essentially the microwave relay system. It takes electricity from the outlet and distributes it to the necessary components. The voltage from the power source flows through the triac into the high voltage diode.
  • Magnetron Tube — The magnetron tube is vital for converting the volt energy supplied from the outlet into the electromagnetic radiation that heats our food. This unit is the primary source of energy for the microwave, so it is one of the harder parts to remove. Magnetic fields produced by the magnetron tube can control electrons, dividing them into radiation energy.
  • Waveguide — One the microwave makes the electromagnetic radiation, the waveguide is responsible for directing that energy into the cooking chamber to heat the food or drink.
  • Control Board — The control board is a specific piece of technology that supplies energy for the low-volt membrane switch. Mostly, the control board reads the orders typed into the touchpad and transfers them to the rest of the microwave.
  • Touchpad — The touchpad is the physical set of buttons that allow users to type in commands and timers. Plastic membranes separate the pins from the electrical switches. When contact initiates, a low-volt electric current initiates which then travels to the control board.
  • Frame — The frame of the microwave holds all of the various components. Inside is the cooking chamber which houses the tray, coupler, and roller guide.
  • Drive Motor — The drive motor is used to propel the roller guide. This movement in term allows the glass tray to spin. The drive motor is attached to the coupler at the base of the microwave chamber.
  • Door Interlock Switch — The door interlock switch is responsible for opening and closing the dooring. Since microwaves stop as soon as the door opens, it is also responsible for interrupting the flow of power.
  • Exhaust fan — All the microwave’s excess energy and heat need a point of exit. That is where the exhaust fan comes in. The fan uses a motor and circulates air throughout the exhaust system to cool it off.
  • Grease catcher — The grease catcher makes sure the fatty oils or food particles do not touch the microwave exhaust system. It catches the particles and filters them out of the air. Remember, the grease catcher will need frequent cleaning, mainly if you use your microwave frequently.
  • High Voltage Diode — Microwaves require more power than the average American outlet can provide. Because of this power discrepancy, microwaves include a high voltage diode to converts the voltage from 115 volts and transforms it into 3000 volts.
  • Coupler — The coupler connects the drive motor and the roller guide. It is a small piece that allows the roller guide to spin.
  • Roller Guide — The roller guide is attached to the coupler. It is the shape of a triangle and has three distinct angles for holding the circle, which contains the glass tray.
  • Tray — A glass tray used to hold the food. The platter usually spins in a circle for a more even cooking. The tray sits on top of the roller guide.

​Basic Microwave Replacement Advice

microwave buttons closeup

The following is some advice on how to replace specific microwave parts. We have included some of the most infamous pieces that usually need replacing. Most of the components will fix simple problems a microwave is having. When ordering microwave parts, make sure to include the specific make and model, as some brands include different cooling systems and electronic schematics.

Also, remember: the capacitor can shock you even if the microwave is unplugged. You also have to discharge the capacitor before repair. You can do this by placing an insulated screwdriver on the capacitor. To insulate a screwdriver, merely wrap electrical tape around the end of the tool.

1

Replace the Touchpad on a Microwave

The first step to replacing a touchpad is unplugging the microwave. Using your microwave’s instructional guide, figure out where you remove the touchpad. Often the pad is held in place with screws so that you will need a screwdriver.

Next, unplug the touchpad’s back-wires from the rest of the microwave. Do not worry; they will not shock you. Replace the old touchpad with the new one and replace the wires in the same spots they were before. Finally, screw the touchpad back into place and plug the microwave back in.

2

Replace the Magnetron Tube on a Microwave

First, unplug your microwave and remove the tray and roller guide. Next, unscrew the three bolts from the upper portion of the microwave. You will need to remove the entire control panel to access the magnetron tube. Pull the case off the microwave and disconnect the main wire from the machine. Once the magnetron is out, remove the limiter from the device. When installing the new magnetron tube, make sure the wires are facing outwards. Reattach the magnetron tube limiter. Reverse assembly (reattach screws).

3

Replace the Drive Motor on a Microwave

When the drive motor is acting up, it will make a harsh, grinding sound. First, unplug the microwave from the wall. To access the drive motor, you will need to open up the bottom of the machine. Use a screwdriver to unscrew any necessary components. Once the panel opens up, you should see the drive motor in the middle of the microwave bottom. It is easy to detach — merely unplug the connecting wire. Apply the same cable to the replacement piece and seal the microwave back up. Then, attach it back into the wall and plug it in.

 

4

Replace the Door Interlock Switch on a Microwave

Any time you are inspecting a door, look at the latch first. Sometimes the lock causes the door to misalign with the switch, which create a malfunction. Replacing the latch is a much easier task than the door interlock switch.

As usual, unplug the microwave. Before removing any parts, test the door interlock switch with a multimeter. If there is no resistance reading, you will need to replace the part. To access the switch, you must discharge the capacitor. As mentioned before, do this with an insulated screwdriver.

Disconnect the current switch from all its surrounding wires. Install the new piece, and reattach the corresponding cables. Then, tighten the screws until the door interlock switch is safely in place. Plug the microwave back into the wall.

5

Replace the Exhaust Fan Motor on a Microwave

First, unplug the microwave unit. You will also need to take it off the wall if you have an overhead group. Locate the motor and rotate it by hand. If the engine does not move, it will need to replace. Unscrew the unit and disconnect the wires attached to it.

Reconnect the wires to the new units and reverse the steps. While you are near your microwave exhaust system, make sure to clean out your grease catcher. A clogged caught can damage the fan motor you installed.

Microwaves are a technological marvel. The different moving parts and components of the machine are mind-boggling when you think about them. You could spend weeks study the schematics of a microwave and still not grasp the intricacies of its design.

Luckily, over the past few decades, microwaves became incredibly user-friendly. Now, with the age of the internet, the microwave parts you need are available with the click of a finger. So, there is no excuse not to order a part online and try your hand at microwave repair.