If your GE microwave isn’t heating, there is most likely something wrong with one or more of the internal components. If this is the case, the faulty component will need to be repaired or replaced before your microwave will start working again.
Before we go any further, we need to make it clear that fixing a microwave requires you to have specialist knowledge and the right tools. This is because it’s a very dangerous task. If your GE microwave isn’t heating and you’re not experienced in working with the internal components of a microwave, you should get a technician to inspect your appliance.
This guide covers all major GE microwave models, including:
Let’s go through the most likely components within your GE microwave that will need to be checked, and if faulty, replaced.
The microwave diode
The diode in your microwave converts the A/C power that comes out of the transformer to D/C so the voltage doubles. This is required for the magnetron to receive enough power to be able to heat food. The diode can sometimes burn out, which means the magnetron won’t get enough power and your microwave won’t be able to operate correctly.
Inspecting the diode requires removing the casing of the microwave and inspecting the diode for signs of damage. If damaged,a new diode will need to be installed. If there is no obvious damage, it will need to be checked with a multimeter to ensure voltage levels are correct. If the voltage levels are incorrect, a new diode must be installed.
Remember, you shouldn’t test a diode unless you have experience working with microwave components. This is due to the microwave storing electricity in the high voltage capacitor, posing a serious risk of electric shock if you don’t handle it properly. The same warning applies to checking all of the other components in your microwave.
The door switch
If the diode is working correctly or if replacing it doesn’t fix your microwave, the next component to check is the door switches. Most microwaves have three or four switches that monitor when the door is open and closed. If one or more of the switches becomes defective, the control board may think the door is open when it isn’t, which will stop your microwave from heating.
The door switches need to be checked with a multimeter for continuity. If any of the switches fail the test, they will need to be replaced. To test the switches, you will need to first locate them and then disconnect them. This will involve removing panels from your appliance. Your owner’s manual will have detailed instructions to help you locate the door switches.
If the door switches are working correctly, or if replacing them didn’t get your microwave working again, the next component to check is the magnetron. The purpose of this component is to generate the frequency that heats your food. If it burns out, your microwave won’t be able to heat.
To check the magnetron, you need to locate it and check for signs that it has burned out. If it has burned out, a new magnetron will need to be installed. If you don’t know where the magnetron is, consult your user manual.
If the magnetron isn’t burnt out, or if replacing it didn’t get your microwave working again, the next component to check is the thermostat. Sometimes the thermostat can become defective and prevent voltage from reaching the high-voltage components within your appliance that heat food.
To determine if the thermostat is faulty, you need to locate it and test it with a multimeter for continuity. If it’s faulty, replace the thermostat. If working correctly, you will need to check the next component.
The high-voltage capacitor
In our guide for how to repair a GE microwave that isn’t heating, the next component to check is the high-voltage capacitor. The purpose of this component is to work with the high-voltage diode to make sure your microwave has enough voltage to operate correctly.
To test the high-voltage capacitor, you need a VOM meter that has a capacitance testing function. If the component is faulty, replace it.
The high-voltage transformer
If the high-voltage capacitor is working correctly, or if you don’t have the correct VOM meter to test it, you will need to check the high-voltage transformer next. This component also helps your microwave generate enough voltage to operate correctly.
You don’t need to test this component with a multimeter. Instead, locate it and check if the transformer has burned out. If so, replace it.
The thermal fuse
If the high voltage transformer is not burnt out, or if replacing it hasn’t fixed your microwave, the next component to check is the thermal fuse. The thermal fuse keeps track of the temperature in your microwave. If it overheats, the thermal fuse tells the control board to switch the microwave off. If it becomes defective, your GE microwave won’t heat.
To determine if the thermal fuse is faulty, you need to locate it and test it with a multimeter for continuity. If faulty, a new thermal fuse will need to be installed. If it’s working correctly, you will need to check the next component.
If the thermal fuse is working correctly, or if replacing it doesn’t get your microwave working again, the next component to check is the thermo-protector. The purpose of the thermo-protector is to switch your microwave off when it overheats. If it’s faulty, your GE microwave will stop heating.
To determine if the thermoprotector is faulty, you need to locate it and test it with a multimeter for continuity. If it’s faulty, it will need to be replaced. If it’s working correctly, you will need to consider replacing the main control board.
The main control board
If all of the components listed above are working, you may need to replace the main control board. The main control isn’t usually the cause of a microwave not heating, but if you have tried everything else, you will need to consider replacing it. You can also consider the option of buying a new microwave instead.