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A broken microwave oven is a common problem that is best addressed to service centers. If you have the skills and experience in repairing electrical equipment, our article will help you identify and fix breakdowns yourself. Before starting the repair, we will analyze the most common malfunctions and how to fix them.
The principle of operation of the microwave
Before you decide to repair the stove yourself, you should understand the design and device of the device. A conventional microwave oven consists of a magnetron, a capacitor, a transformer, a diode, and a fan. In modern models, you can find auxiliary elements, such as a grill.
Magnetron
The heart of the microwave is called the magnetron, the energy of which is converted into heat. This principle of operation is available due to the anode-filament stabilizer (transformer). The body of the electronic device is placed in a special plate radiator, which is constantly blown by a fan. To prevent the part from overheating, it is equipped with a special thermal fuse. In the early microwave ovens, it was the magnetron that took the lion’s share of the cost. However, over time, the price became affordable, after which mass production was launched.
Fun
Another important element in the design of the device is a fan, due to which the chamber, magnetron and grill are blown. The fan allows the accumulated air and water vapor to escape. Air circulation in the chamber is available through air ducts, which are located inside the microwave oven.
shielded camera
Regardless of the cost and model, any stove has a shielded chamber. Metal-protected chamber prevents microwave radiation from escaping. There is a special grid on the glass, which is designed to hold the rays inside the microwave. It is also necessary to ensure that the door always fits snugly against the body. Do not use the device if the door is not closed.
Блок управления
The control panel is designed to control and maintain the installed power of the device. These functions can be called basic. More advanced models have advanced functionality, which includes: a timer, time and power indicators, automenu programs, sound alarms, and others.
Important! Never run the microwave on idle. One of the consequences of neglecting this rule is the failure of the magnetron, which costs as much as half a microwave oven.
accident prevention
Do not forget that it is possible to carry out repair actions with a microwave only if you have experience with electrical engineering. In addition, you should follow all the safety rules specified in the instructions for use.
The list of basic rules for device repair:
- It is forbidden to start the device if the door does not fit snugly against the body.
- The stove should be repaired only after disconnecting from the mains and completely discharging the capacitor.
- It is allowed to replace parts only with high-quality analogues.
- Never start the stove with a faulty blower system.
- Before carrying out the diagnosis, it is necessary to put a container of water inside in advance.
Diagnostics and troubleshooting
High voltage fuse blown
Among the common breakdowns, one can distinguish a malfunction of the high voltage fuse. In the event of a breakdown, the microwave stops turning on and responding to button presses. Before carrying out diagnostics, it is necessary to discharge the high voltage capacitor, and then remove the protective cover by unscrewing the fastening screws. Next, using an ammeter, you should check the voltage in the surge protector.
Most often, the diode is located on the power filter board. If a part burns out, it must be replaced immediately. After repair, it is necessary to find out the cause of the overload, due to which the fuse has failed.
If swelling or darkening is found on the parts of the device, it is necessary to check the control unit. If after replacing the fuse nothing has changed in the operation of the device, the problem may lie in the transformer board.
Magnetron failure
This is the most common malfunction that awaits microwave oven owners. If the stove does not warm up, it is necessary to deal with the operation of the magnetron. To detect damage, inspect the inner walls of the device. If there is no mechanical damage, remove the plate on the left side of the compartment and clean it with a mild alcohol solution. After cleaning, you can proceed to check the health of the element. If darkening or burnt holes are found, replace the faulty mechanism.
After cleaning the surfaces, you can proceed to the diagnosis of the unit. To detect a breakdown, visually inspect the condition of the insulation between the device case and the terminals. The resistance in the diagnosed area indicates a malfunction of the capacitors in the filter. In this case, the repair may be limited to replacing the filter unit and condenser. Next, inspect the metal cap and, if damaged, replace with a new one.
burnt mica plate
Another common cause of microwave failures is a burnt mica plate. However, this malfunction can be repaired with your own hands. One of the symptoms of a breakdown is sparks in the zone of the wave channel. Why did this happen and how to fix it?
During cooking, some products may splatter, the consequence is the soaking of mica. To avoid future damage, cook and reheat food only in sealed containers. So, what to do if it was not possible to prevent burnout:
- Stock up on working tools: scissors, sandpaper, an awl and a needle file.
- Unscrew the top cover and the appliance door.
- Take out the old plate and magnetron.
- File the slot of the waveguide with a file.
- Get rid of the sharp metal edges resulting from the burning of the mica.
- Clean the wave channel with sandpaper.
- Treat burnt parts of equipment.
- Remove dirt from the inner chamber and wave channel.
- Examine the magnetron block.
- Replace the metal cap if necessary.
- Using the instructions, install the magnetron.
- Screw on the doors.
- Start the stove by placing a bowl of water inside.
- Apply a new layer of mica to the burnt plate.
- Circle the outline of the plate with an awl.
- Install the mica plate.
Other possible breakdowns
In addition to the main breakdowns, there are others that are much less common, but give users a lot of trouble. Let’s find out what to do if the microwave is not working, the drip tray is not spinning, or the display is not working.
Backlight failure
What to do if the light is not on? The backlight of the microwave oven turns on during operation or when the door is opened. The simplest reason why it does not work is the burnout of the light bulb. In rare cases, the problem lies in the backlight itself. If the light bulb can be replaced by yourself, then it is better not to repair the backlight with your own hands. In order to avoid serious damage, it is recommended to contact a specialist.
Fuse defective
A common problem after a power surge is a blown fuse. This failure may be the reason that the stove does not turn on. If replacing the fuse does not help, the transformer or diode is faulty.
Dish rotates unevenly
If the plate is spinning jerkily, then the rollers should be thoroughly cleaned. Was the cleaning ineffective? Probably the platter motor is not working. In this case, the part should be replaced.
Fan failure
If the stove turns off and on again by itself, the reason lies in poor ventilation. To eliminate the breakdown, you will need to clean the cooling grilles and regular channels, and then check the operation of the device.
The device is not working
The microwave does not work, while the fuse, plug and cable are working – it may be a faulty diode or transformer. It is difficult to say how to act in such a situation. Models from Panasonic or Samsung may have their own design features. In order not to completely break the device, it is recommended to contact the master.
Microwave won’t turn off
If the oven does not turn off, while the light inside the chamber is on, the tray rotates, and the appliance itself turns off only if the plug is unplugged from the socket, the cause of the malfunction is one of several door microswitches. To determine the exact cause, it is necessary to disassemble the device, and then check the limit switches. We do not recommend disassembling the device yourself. If your model is from LG, Daewoo, Bosch or Siemens, then the right decision would be to contact the official service center. If the microwave is a budget and little-known model, it is recommended to call a repairman or send the technician to the workshop.
Now you know what to do if your microwave oven does not show signs of life, or vice versa, it does not turn off at all. Knowing what can burn or break and how to disassemble the device, you can eliminate the bulk of the problems that have arisen. The main thing is not to forget about the precautions, safety precautions and instructions that you will definitely need.