Microwave does not heat up food: reasons, repair

Imagine the situation: going to work in the morning, you were left without a hot sandwich: the microwave does not heat up the food. Outwardly, everything is in order – the stove shines, turns, but does not heat up. Let’s figure out what the problem is and what to do in this case.

How a microwave oven works

First, let’s explain how it works. The basis of the machine is the magnetron, which creates an electric field. It acts on the liquid molecules in the product. They start moving. When they rub against each other, heat is generated. Due to this, as well as the use of additional devices, the equipment performs many functions – heating, defrosting, grilling and others.

Microwave Care Instructions

Compliance with simple recommendations will allow the home assistant to serve for a long time:

1. Do not use metal containers or utensils with metallic coatings for cooking. The oven, acting on them, heats the dishes themselves, and not the food.
2. Do not put eggs, vegetables, fruits and other products in which there is a lot of water in open containers. Heating up from the inside, they will burst and splatter the chamber.

3. 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, cannot serve forever. Practice shows that the equipment of these manufacturers, like Sharp, Scarlet, Panasonic, Supra, Bosch, works fine for 5-7 years. Then problems may arise.

For example, outwardly everything seems to work, but the food is poorly heated or not heated at all. At the same time, the unit makes noise or squeaks, but the stand is spinning at the same time. Heats up food for a long time. Not always such signs indicate that the microwave is broken and needs to be carried in for repair. Why it doesn’t work remains to be seen. Let’s go from simple to complex.

• It happens that the user, in a hurry or out of forgetfulness, did not switch the mode on the display from defrosting to cooking. As a result, the oven heats poorly.
• For normal operation, a mains voltage of 220 volts is required. Dropping it even by 10–20 volts will cause the stove to heat poorly. Use an uninterruptible power supply or voltage stabilizer.
• Sometimes the owners turn on several electrical appliances at the same time using tees and extension cords. Then the socket does not withstand the load, the equipment heats up poorly or turns off. Use a separate power supply for each instrument.
• If the microwave has become worse to heat or heats up every other time, the cause may be a loose fit of the chamber door. It is necessary to readjust its latch.

If all this does not help, let’s look deeper into the problem and try to find the cause of the breakdown. The microwave oven buzzes, buzzes, stops heating, but it works if the following are out of order:

1. Door switch.

2. One of the fuses.

3. diode or capacitor.

4. Magnetron.

The problem may also be in the inverter if your microwave is of the appropriate type.

Some malfunctions can be fixed by yourself, while others are better handled by a specialist. Statistics say that in four out of five cases, after self-repair, you still have to contact the workshop.

Repair by own hands

Before starting work, make sure that the warranty period of your equipment has expired, otherwise you will lose the possibility of free service at the service center.

You will need:

• Screwdriver Set;
• passages;
• soldering iron;
• ammeter;
• rubber gloves (you can use thin household ones).

Read the instructions first. For example, in the Samsung microwave passport, the causes of common malfunctions are considered and ways to eliminate them are explained.

Attention! The microwave oven uses high voltage. Even when disconnected from the network, it remains on the capacitors for some time. Therefore, after de-energizing the device, wait 10 minutes or discharge the parts.

After unscrewing the screws on the rear wall, carefully remove the housing cover. Inspect the device carefully, using a flashlight if necessary. An unpleasant smell of burning insulation, obvious deformation of parts, cracks or smudges will immediately tell you the place of the breakdown.

In the absence of these signs, proceed with the search.

First of all measure with a voltmeter mains voltage and ringing wire stoves.

Verify with a tester that the operating voltage at transformer primary winding also 220 volts.

Next check with an ohmmeter. door microswitch. If it is working, the scale will show more than zero.

Visually inspect fusible mains fuse. The absence of thin wiring inside says that it has burned out. You can check its resistance with a device.

Next call high voltage fuse which is covered with a casing. The ohmmeter needle should deviate from 0 when it is intact.

Now let’s move on to testing multiplierconsisting of a diode and a capacitor. The arrow of the ammeter voltmeter deviated to the maximum shows a workable capacitor. In the event of its breakdown, the part must be replaced along with the diode.

Before checking feedthrough capacitors with an electrically insulated screwdriver, short their leads to the case. With one probe of the measuring device we touch the contact of the part, and with the second – the metal. The sensor should show no resistance. So the capacitor is good. After that, we test it for a test. There should be a resistance of 0,1 ohm between the capacitance contacts.

Turning on for five minutes with a glass of water in the microwave chamber, measure the voltage in the primary winding with an ammeter. transformer. It must be 220 V.

Having bought in a specialized store or on the radio market the parts corresponding in parameters, replace the defective ones with a soldering iron.

And finally test magnetron. On examination, its breakdown is indicated by soot. If this is not the case, look at the soldering points of the coil contacts and the connections to the capacitors. Clean or solder them. The resistance of the filament of the node during continuity should be 2-3 ohms.

You should not change this most important element of the microwave oven on your own, so as not to permanently disable the equipment!

With the determination of the reason why your device stopped heating, and with its repair, with experience and the necessary tools, you can handle it yourself.

The above will help you with this. Good luck!