A bad magnetron in a microwave can cause the appliance to make loud humming noises, produce no heat, or burn or blow a fuse. These symptoms indicate that the magnetron, which is the component that generates microwaves, is malfunctioning or failing. In this article, we will explain what a magnetron is, how it works, and how to diagnose and fix a bad magnetron in a microwave.
A magnetron is a type of vacuum tube that converts electrical energy into electromagnetic waves, or microwaves. It consists of a cathode, an anode, and a pair of permanent magnets. The cathode is a heated filament that emits electrons, while the anode is a metal cylinder with holes called cavities. The magnets create a magnetic field that forces the electrons to move in a circular path around the anode. As the electrons pass by the cavities, they induce an alternating electric field that resonates inside the cavities and produces microwaves. The microwaves then exit the magnetron through a waveguide and are directed to the cooking chamber of the microwave oven.
How to diagnose a bad magnetron in a microwave?
A bad magnetron in a microwave can cause several problems, such as:
Loud humming noises: A normal magnetron should produce a low humming sound when it operates. However, if the magnetron is damaged or worn out, it can create a loud buzzing or humming noise that indicates that it is struggling to generate microwaves. This noise can also be caused by other faulty components, such as the high voltage diode, the capacitor, or the fan motor, so it is important to check them as well.
No heat: A common symptom of a bad magnetron is that the microwave does not heat the food or water, even though it appears to be working normally. This means that the magnetron is not producing enough microwaves, or that the microwaves are not reaching the cooking chamber. This can be due to a defective magnetron, a broken waveguide, a faulty door switch, or a misaligned stirrer blade.
Burned or blown fuse: A bad magnetron can also cause the microwave to burn or blow a fuse, which will prevent the appliance from turning on or running. This can happen if the magnetron draws too much current, or if it creates a short circuit. A burned or blown fuse can also be caused by other issues, such as a faulty transformer, a defective thermostat, or a loose wire, so it is advisable to test them as well.
To diagnose a bad magnetron in a microwave, you will need a multimeter, a screwdriver, and a pair of gloves. Before you begin, make sure to unplug the microwave and discharge the high voltage capacitor to avoid electric shock. Then, follow these steps:
Remove the microwave cover by unscrewing the screws that hold it in place.
Locate the magnetron, which is usually a silver or black box with two wires attached to it. Disconnect the wires from the terminals of the magnetron.
Set the multimeter to the lowest resistance setting and touch the probes to the terminals of the magnetron. The multimeter should read less than one ohm. If the multimeter reads infinity or a very high resistance, the magnetron is open and needs to be replaced.
Touch one probe of the multimeter to one terminal of the magnetron, and the other probe to the metal casing of the magnetron. The multimeter should read infinity or a very high resistance. If the multimeter reads zero or a very low resistance, the magnetron is shorted and needs to be replaced.
How to fix a bad magnetron in a microwave?
If you have diagnosed that the magnetron is bad, you will need to replace it with a new one. You can buy a compatible magnetron online or from a local appliance store. To replace the magnetron, you will need a screwdriver, a pair of gloves, and a new magnetron. Then, follow these steps:
Unplug the microwave and discharge the high voltage capacitor to avoid electric shock.
Remove the microwave cover by unscrewing the screws that hold it in place.
Locate the magnetron, which is usually a silver or black box with two wires attached to it. Disconnect the wires from the terminals of the magnetron.
Unscrew the screws that secure the magnetron to the microwave and remove the magnetron from the appliance.
Install the new magnetron by aligning it with the mounting holes and securing it with the screws. Reconnect the wires to the terminals of the magnetron.
Replace the microwave cover and plug the appliance back in.
Test the microwave by heating a cup of water for a few minutes and checking if it is hot.
A bad magnetron in a microwave can cause the appliance to make loud humming noises, produce no heat, or burn or blow a fuse. These symptoms indicate that the magnetron, which is the component that generates microwaves, is malfunctioning or failing. To diagnose a bad magnetron, you will need a multimeter, a screwdriver, and a pair of gloves. To fix a bad magnetron, you will need a screwdriver, a pair of gloves, and a new magnetron. By following the steps in this article, you can diagnose and fix a bad magnetron in a microwave and enjoy your hot meals again.
