How does a microwave oven work?
Before you decide to repair the stove yourself, you should understand the design and structure of the device. A conventional microwave oven consists of a magnetron, capacitor, transformer, diode and fan. Modern models can have auxiliary elements, such as a grill.
Magnetron
The heart of a microwave oven is called a magnetron, the energy of which is converted into heat. This operating principle is available due to the anode-filament stabilizer (transformer). The housing 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 first microwaves, 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.
Fan
Another important element in the design of the device is a fan, thanks to which the chamber, magnetron and grill are blown. The fan allows accumulated air and water vapor to escape. Air circulation in the chamber is available through air ducts located inside the microwave.
Shielded chamber
Regardless of the cost and model, any stove has a shielded chamber. The metal-protected chamber prevents microwave rays from escaping. There is a special mesh on the glass, which is designed to hold the rays inside the microwave. It is also necessary to ensure that the door always fits tightly to the body. Do not use the device if the door does not close.
Control block
The control panel is designed to control and support the installed power of the device. These functions can be called basic. More advanced models have expanded functionality, which includes: timer, time and power indicators, auto menu programs, sound alarm and others.
Important! Never turn on the microwave without power. One of the consequences of neglecting this rule is the failure of the magnetron, which costs as much as half a microwave oven.
Safety precautions
Do not forget that repairs to a microwave oven can only be carried out if you have experience working with electrical engineering. In addition, you should adhere to all safety rules specified in the instructions for use.
List of basic rules when repairing a device:
- It is forbidden to start the device if the door does not fit tightly to the body.
- The stove should be repaired only after disconnecting from the power supply and completely discharging the capacitor.
- It is allowed to replace parts only with high-quality analogues.
- Never operate a stove with a faulty fan system.
- Before carrying out diagnostics, it is necessary to place a container of water inside in advance.
Magnetron faulty
In this case, the microwave does not heat, but hums and hums. To determine whether the possible cause of the malfunction lies in a broken magnetron, it is necessary to open the case, disconnect the magnetron terminals from the power circuit and touch them with ohmmeter probes. A working device should produce a resistance of 2-3 ohms, a faulty one will not react to touch. If the experiment shows that the magnetron is not working properly, it will need to be replaced. As practice shows, replacement in many cases is impractical, since a new spare part will cost up to 60% of the cost of a new microwave.
Diagnosis and Troubleshooting
High voltage fuse blown
Among the common breakdowns is a malfunction of the high voltage fuse. In the event of a breakdown, the microwave stops turning on and no longer responds to button presses. Before carrying out diagnostics, it is necessary to discharge the high-voltage capacitor, and then remove the protective casing by unscrewing the fastening screws. Next, using an ampere-voltmeter, 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 should be replaced immediately. After the repair, it is necessary to find out the cause of the overload, which is why the fuse 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 there is no change in the operation of the device, the problem may lie in the transformer board.
Magnetron malfunction
This is the most common malfunction that awaits microwave oven owners. If the stove does not heat up, you need to understand the operation of the magnetron. To detect damage, inspect the internal walls of the device. If there is no mechanical damage, remove the plate from the left side of the compartment and clean it with a weak alcohol solution. After cleaning, you can begin checking the functionality of the element. If darkening or burnt holes are detected, replace the faulty mechanism.
After cleaning the surfaces, you can begin diagnosing the unit. To detect a breakdown, visually inspect the condition of the insulation between the device body and the terminals. Resistance in the area being diagnosed indicates a malfunction of the capacitors in the filter. In this case, repairs may be limited to replacing the filter and capacitor unit. Next, you should inspect the metal cap and, if damaged, replace it with a new one.
Burnt mica plate
Another common cause of microwave problems 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 wave channel area. Why did this happen and how to fix it?
During the cooking process, some products may splatter, resulting in the mica becoming soggy. To avoid future damage, cook and reheat food only in sealed containers. So, what to do if you couldn’t prevent burnout:
- Stock up on working tools: scissors, sandpaper, an awl and a file.
- Unscrew the top cover and door of the device.
- Take out the old plate and magnetron.
- Use a file to file the waveguide slot.
- Get rid of sharp metal edges caused by mica burning.
- Clean the wave channel with sandpaper.
- Treat burnt equipment parts.
- Remove dirt from the inner chamber and wave channel.
- Inspect the magnetron unit.
- Replace the metal cap if necessary.
- Using the instructions, install the magnetron.
- Screw the door leaves.
- Start the stove by placing a bowl of water inside.
- Apply a new layer of mica to the burnt plate.
- Trace the outline of the plate using an awl.
- Install the mica plate.
Other possible breakdowns
In addition to the main breakdowns, there are others that are much less common, but cause users a lot of trouble. Let's find out what to do if the microwave oven does not work, the tray does not spin, or the display does not work.
Backlight failure
What to do if the light doesn't light up? The microwave oven light turns on during operation or when the door is opened. The simplest reason why it doesn't work is the light bulb burns out. In rare cases, the problem is the backlight itself. If the light bulb can be replaced yourself, then it is better not to repair the backlight yourself. To avoid serious damage, it is recommended to contact a specialist.
Fuse failure
A common problem after a power surge is a blown fuse. This breakdown may be the reason why the stove does not turn on. If replacing the fuse does not help, the transformer or diode is faulty.
The plate rotates unevenly
If the plate spins jerkily, the rollers should be thoroughly cleaned. Was the cleaning ineffective? The dish motor is probably not working. In this case, the part should be replaced.
Fan fault
If the stove turns off and turns on again by itself, the reason lies in poor ventilation. To eliminate the breakdown, you will need to clean the cooling grilles and standard channels, and then check the operation of the device.
Device is not working
The microwave does not work, but the fuse, plug and cable are fine - 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. To avoid permanently breaking the device, it is recommended to contact a specialist.
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 pulled out of the socket, the cause of the problem 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 the manufacturers, Daewoo, Bosch or Siemens, then the right decision would be to contact an official service center. If the microwave is a budget and little-known model, it is recommended to call a repairman or send the equipment to a workshop.
Now you know what to do if your microwave oven shows no signs of life or, on the contrary, 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 arise. The main thing is not to forget about precautions, safety precautions and instructions that will definitely come in handy.
Special products for removing stench from burnt food
To remove the burning smell from a microwave oven, you can use specialized compounds that are sold in online markets and in departments with household chemicals. Top 3 effective remedies:
Wpro
Microwave oven cleaner effectively eliminates unpleasant odors and washes various types of dirt without harming the microwave surface.
The composition is based on anionic and nonionic surfactants . The product has an antibacterial effect and is sold in a convenient bottle equipped with a sprayer. Price – 690 rubles.
Mr. Chister
This is an effective composition that not only removes dirt, but also copes with persistent odors. The spray works very quickly. It is sprayed onto the surface of the oven, left for 3 minutes, and then washed off with water.
With one click on the bottle, a large area is irrigated , which allows you to effectively use the oven and microwave cleaner. Price – 165 rubles per package.
BON
This is a highly effective spray that is designed to eliminate various types of dirt. It is based on asurfactants and nsurfactants.
In addition to grease and soot, the liquid copes well with foreign odors, although it itself smells quite sharp. Therefore, after using it, the oven must be ventilated for several hours.
Microwave oven cleaner is used very economically , thanks to the convenient spray bottle. A 500 ml package will last a long time. Price – 350 rubles.
When working with sprays, you should not allow them to come into contact with the skin of your hands, as they can cause irritation. The compositions must be used strictly according to the instructions, without overexposing them to the surface of the oven.
