Today, microwaves are one of the essential tools in kitchens. In addition to cooking food, this device also helps us heat food. If the microwave does not turn on, we may get in trouble. There are several reasons why a microwave oven does not turn on. To diagnose them, you should carefully consider various factors such as ceramic fuses, door switches, thermal fuses, door locks, main components such as magnetrons, high voltage diodes and related wire terminals. In this post from RepairLand, we will look at the reasons why the microwave does not turn on. Reading this post can help you find a solution to the problem of microwave not working.
Reasons why the microwave does not turn on and how to fix them
- Ceramic fuse
- Door switch
- Thermal fuse failure
- door lock
- Diode failure
- Magnetron burning
If the ceramic fuse fails, the power to the microwave control is cut off and the appliance does not turn on. The ceramic fuse is designed to protect the microwave components in the event of severe power fluctuations or in the event of a major defect in one of the microwave’s internal components. Failure of this part will cause the power in the microwave to be completely lost and the microwave will not turn on. When the fuse breaks, the power in the microwave control is cut off and the microwave no longer works. Also, the screen does not turn on. If the fuse is broken for any reason, it is necessary to check the main components such as magnetron, high voltage diode, capacitor and transformer and related wire terminals before replacing the fuse. You can check the fuse using a multimeter. The ceramic fuse is located inside the microwave cabinet and near the entry point of the power cord. If you need to replace the fuse, be sure to use the part number recommended by the manufacturers mentioned in the manual.
Another reason why the microwave does not work can be due to a defect in the door switch. Most microwave ovens have three or four door switches. The door switches operate sequentially to ensure that the door is closed properly. If any of the door switches break down, the microwave will not work or heat up. Door switches, often referred to as primary or secondary connection main switches, when the microwave door is closed by other microwave components, the appliance starts working and when the door is opened, the power is cut off. . Sometimes all the components of the microwave, such as the screen, may look healthy, but the microwave will not work, in which case the door switch may be damaged. The door switch is located inside the microwave cabinet and is activated by a hook or latch on the door. If you are going to test the door switch, first unplug the microwave from the power outlet before doing anything. Use a multimeter to inspect and repair the microwave door. To access the door switch, detach the front panel of the microwave and remove the door switch. Set the multimeter to rx1 to check the connection. Press the door open and close button and touch the terminals. If 0 is displayed on the multimeter, it means that there is a connection. If not, you must replace the door switch.
Thermal fuse failure
If your microwave does not turn on, the thermal fuse may be off. Microwaves use one or more heat slices, sometimes called thermal fuses, to protect the heat in the microwave from overheating. These thermal fuses are often located inside the cabinet, near the magnetron. If the thermal fuse breaks, it is cut off to maintain electrical safety at the controls or control outlets to prevent the microwave from overheating. In this case, you must remove the cabinet housing and find the disconnected heat fuse and disconnect the wires from the terminals. Then check the circuit with a multimeter. If there is a problem, you must replace the thermal fuse. Also make sure that the cooling fan is working and the air flow is not limited.
Another thing that keeps your microwave from turning on is a problem with the door lock. The door lock consists of two parts, one microswitch and one hook. The hook protrudes from the door and is located in the door switch holder, which is mounted on the microwave frame. The hooks contact the door keys to power the controls and also lock the retainer to close the door. The door lock is usually made of plastic that attaches to the door and engages the door switch when the door is closed, signaling the rest of the controls to the microwave, and usually has a spring connected to create downward tension for Hold the hooks. If any of the hooks are broken, the door may not close. If you notice any signs such as cracking, wear, discoloration in the door lock assembly, it is necessary to replace the door lock. To do this, you must remove the door panel to access the door lock. The inner panel is closed by plastic fasteners so be careful when opening.
The output diode converts the AC power of the transformer to dc and doubles the voltage to nearly 5000 volts. This high voltage provides the magnetron energy needed to heat food. If the diode breaks down, the magnetron will not receive enough voltage to heat the food. If the diode is burned out, you must replace it. To check the health of the diode, you should use a multimeter that uses a 9-volt battery or insert the 9-volt battery in series with the diode. When the wires are reversed, the diode should only have one direction in one direction.
Important Note: The microwave can store a significant amount of electricity even after being cut off in its high voltage capacitor. There is a possibility of electric shock when replacing microwave electronic components due to high voltage. Therefore, only a qualified technician is allowed to replace the diode.
The magnetron uses high voltage and high dc current to generate the microwave frequency that supplies the food. If the magnetron burns, the microwave does not heat up and does not turn on. Also, the magnetron cannot be repaired and if the magnetron is burned, you must replace it.
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