Imagine a situation: when you were going to work in the morning, you were left without a hot sandwich: the microwave does not heat food. Outwardly, everything is in order - the furnace shines, turns, but does not heat up. We'll figure out what the problem is and what to do in this case.
How a microwave oven works
First we explain the principle of its action. The basis of the machine is a magnetron, which creates an electric field. It acts on the liquid molecules in the product. They begin to move. When rubbing them against each other, heat is generated. Due to this, as well as the use of additional devices, the technician performs many functions - heating, defrosting, grilling and others.
Microwave Care Guidelines
Compliance with simple recommendations will allow a home assistant to serve for a long time:
- Do not use metal containers or metallic cookware for cooking. The oven, acting on them, heats the dishes themselves, and not the food.
- Do not lay eggs, vegetables, fruits and other products in which there is a lot of water in an open container. When heated from the inside, they will burst and splatter the camera.
- To avoid fire, do not turn on the appliance without loading food.
Causes of malfunctions
Even the products of such well-known companies as LG, Samsung, Daewoo, can not last forever. Practice shows that the equipment of these manufacturers, like Sharp, Scarlet, Panasonic, Supra, Bosch, works perfectly for 5-7 years. Then problems may arise.
For example, everything seems to work outwardly, but the food does not warm up well or does not warm at all. At the same time, the unit is noisy or beeping, but the stand is spinning at the same time. Heats food for a long time. Not always such signs indicate that the microwave is broken and must be carried in for repair. Why it does not work, you need to find out. Let's go from simple to complex.
- It happens that a user in a hurry or out of oblivion did not switch the mode from defrosting to cooking on the display. As a result, the oven heats slightly.
- For normal operation, a voltage of 220 V is required. Falling it even at 10-20 Volts will lead to the fact that the stove heats poorly. Use an uninterruptible power supply or voltage regulator.
- Sometimes the owners simultaneously connect several electrical appliances to the network using tees and extension cords. Then the outlet does not withstand the load, the equipment does not warm up well or turns off. Use a separate power source for each device.
- If the microwave becomes worse warming or warms through once, the cause may be a loose fit of the chamber door. It is necessary to adjust its latch.
If all this does not help, look deeper into the problem and try to find the cause of the breakdown. The microwave oven buzzes, buzzes, stops heating, but at the same time it works if the following fail:
- Door switch
- One of the fuses.
- Diode or capacitor.
- Magnetron.
The problem may also be in the inverter if you have the appropriate type of microwave.
Some problems can be repaired by oneself, while others are better managed by a specialist. Statistics say that in four out of five cases, after self-repair, you still have to go to the workshop.
DIY repair
Getting started, make sure that the warranty period of your equipment has expired, otherwise you will lose the possibility of free maintenance in the service center.
You will need:
- screwdriwer set;
- pliers;
- soldering iron;
- ampervoltmeter;
- rubber gloves (you can thin household).
Re-read the instructions first. For example, the Samsung microwave passport examines the causes of common failures and explains how to fix them.
Attention! The microwave uses high voltage current. Even when disconnected from the network, it is stored on capacitors for some time. Therefore, after switching off the device, wait 10 minutes or discharge the parts.
Having unscrewed the screws on the rear wall, carefully remove the housing cover. Carefully inspect the device, using a flashlight if necessary. The unpleasant smell of burning insulation, obvious deformation of parts, cracks or smudges will immediately tell you where the breakdown is.
In the absence of the listed signs, proceed with the search.
First measure with a voltmeter mains voltage and ring the wire of the stove.
Check with a tester that the operating voltage is transformer primary also 220 volts.
Next, check with an ohmmeter door microswitch. If it is working, the scale will show more than zero.
Visually inspect the fusible mains fuse. Lack of thin wiring inside says it is burned out. You can check its resistance with the device.
Next call high voltage fuse, which is shrouded. The ohmmeter arrow should deviate from 0 at its integrity.
Now let's move on to testing multiplierconsisting of a diode and a capacitor. The arrow of the ampervoltmeter, which deviates to a maximum, indicates a working capacitor. In case of breakdown, the part must be replaced with the diode.
Before checking feed capacitors with an insulated screwdriver, close their terminals to the housing. One touch of the measuring device touches the contact of the part, and the second - metal. The sensor should indicate a lack of resistance. So the capacitor is working. After that, we check it for a breakdown. Between the contacts of the capacitor there should be a resistance of 0.1 ohms.
Turning on for five minutes with a glass of water in the microwave chamber, measure the voltage in the primary winding with a voltmeter transformer. It should be 220 V.
Having bought parts that are suitable for the parameters in a specialized store or on the radio market, replace the defective parts with a soldering iron.
And finally, test magnetron. On its failure during inspection says soot. If this is not the case, look at the places of soldering the contacts of the coils and the connection to the capacitors. Strip or solder them. The resistance of the filament of the node during the continuity should be 2-3 Ohms.
This important element of the microwave oven is not worth changing on its own, so as not to permanently damage the equipment!
With the determination of the reason why your appliance stopped heating, and with its repair, if you have the experience and the necessary tool, you can deal with it yourself.
The above will help with this. Good luck!