How to Repair a KitchenAid Microwave That Won’t Start

There aren’t many tasks that are quicker or easier than warming up a meal in your microwave. Unfortunately, the convenience of a speedy breakfast, lunch, or dinner can quickly get ruined when your appliance won’t start. If you’re dealing with a built-in KitchenAid microwave model KMBP107EBS that refuses to turn-on, reading the repair guide below may help you pinpoint and fix the malfunction.

Whether you’re repairing a microwave or dishwasher, turning off its power supply at the circuit breaker should always be your first step. Protecting your hands and eyes by wearing work gloves and goggles is another safety precaution you should take before you start inspecting and disassembling your appliance.

The Cut-Off Thermostat

Your microwave has a safety device inside it called a cut-off thermostat. The purpose of a cut-off thermostat is to ensure your appliance does not overheat. If the thermostat senses your microwave is getting too hot it will quickly turn the appliance off. Unfortunately, a damaged cut-off thermostat can block your microwave from turning on. Resolving this issue requires you to replace the faulty component for a new one.

How to Replace the Cut-off Thermostat in Your KitchenAid Microwave

1. Before you can access the cut-off thermostat, you’ll need to extract the microwave from your kitchen cabinet. First, open the microwave door and take out the turntable and the turntable support. Once both parts are removed, unthread the screws holding the mounting brackets to your kitchen cabinet. Then, with the help of a family member, pull the microwave forward and carry it to a stable and flat table close to your kitchen cabinet.
2. Take out the screws holding the top panel to the microwave. Then, pick up the front of the panel and push forward on the back of the panel to take it off your appliance. With the components on the top of the microwave exposed, you can take out the cut-off thermostat, which is located at the front of the appliance near the grill. To do so, simply use a screwdriver to unthread the screws securing it to the inside of the microwave. Once the thermostat is loose, disconnect the two wires running to the component.
3. Grab your new cut-off thermostat, and start installing it by connecting the wires to the thermostat terminals. Next, place the part back in the microwave and rethread its mounting screws to hold the thermostat in place.
4. With the new cut-off thermostat secure, you can reinstall the top panel. Once the panel is connected, ask a family member to help you move your microwave to the opening in your kitchen cabinet. Then, slide the appliance all the way back and secure its mounting brackets. Replace the turntable support and turntable before closing the microwave door.
5. Switch on the circuit breaker, and warm up a glass of water or some food to test out your repair.

The Door Switch

When you close your microwave door, the door switch is activated, meaning it provides power to some of the components in the appliance. On the other hand, when you open your microwave door, the door switch cuts off power to the microwave, which is why your appliance shuts down. A defective door switch can restrict power, causing your microwave to cease functioning even when the door is closed.

How to Replace the Door Switch in Your KitchenAid Microwave

1. You’ll need to remove the appliance from the cabinet before you can replace the door switch, so follow step one in the cut-off thermostat repair guide provided above.
2. Now take off the microwave’s top panel by unthreading the screws securing it, and lifting the panel up and off the appliance. Next, remove the screws holding the right, side panel to the appliance. Once the screws are out, pull the side panel off your microwave.
3. With the top and side panel removed, locate the door switch and disengage the locking tab holding the component inside the door switch housing. Before you disconnect the wires running to the switch, take a quick picture of them to ensure you know the proper placing of each wire. Next, disconnect the wires from the door switch.
4. Retrieve the new door switch, and start installing it by first connecting the door switch wires to the door switch terminals. If you don’t remember the proper placement of the wires, take a look at the picture you took earlier. Once the wires are attached, push the door switch into its housing.
5. With the new door switch installed, you can start putting your microwave back together. First, reattach the side panel, and rethread its screws to secure the part to your microwave. Then, place the top panel back on and reattach the screws you took out earlier. Finally, with the help of a family member, move your microwave back to the opening in your cabinet and replace the mounting screws that hold the appliance in place. Reinsert the turntable support and turntable.
6. Turn on the microwave’s power supply and test out the repair to ensure the new door switch corrected the malfunction.

The Temperature Sensor

As the name implies, the temperature sensor regulates the temperature inside your microwave. If the component is malfunctioning, it can prevent your appliance from turning on. Replacing the sensor is a simple repair that should take you no more than an hour.

How to Replace the Temperature Sensor in Your KitchenAid Microwave 

1. Once again, you’ll need to remove your microwave from your cabinet by following step one in the cut-off thermostat repair guide.
2. After your appliance is no longer attached to your cabinet, unthread the screws holding the rear panel to your microwave. After you’ve lifted the panel off your appliance, locate the temperature sensor near the top of the convection housing. The sensor is held in place by a mounting bracket. Unthread the screw securing the bracket, and then pull the sensor out of the small opening it sits in.
3. Now you’ll need to take off the microwave’s top panel. Once the panel is removed, find the appliance’s main control board, and disconnect the sensor wires from the board. Then, pull the wire out of the small opening in the back of your microwave.
4. To install the new temperature sensor, thread the wire through the opening in the back of your microwave, and attach the wire to the main control board. Next, place the temperature sensor into the opening and secure it with the mounting bracket and screw you took out at the start of the repair. Then, replace the top panel and rear panel.
5. Finish off your repair by reinserting your microwave into the opening in your cabinet, and then securing the sides of the appliance to the sides of the cabinet. Next, replace the turntable support and the turntable and close the microwave door. Finally, shut the appliance door and turn the power back on.

If your microwave isn’t starting and none of the repairs above correct the malfunction, please contact us today and one of our highly trained technicians will help you diagnose and repair the faulty component.