Do-it-yourself microwave repair does not heat

In detail: repairing microwave ovens with your own hands does not warm up from a real master for the site my.housecope.com.

Why does the microwave not heat, but the plate rotates and the light is on? The fan hums and the food is cold. What to do and where to go? When the equipment, which now costs a lot of money and is really needed in the kitchen, can not be thrown away, but simply repaired, all the knowledge on repairing electrical appliances is used. To achieve a positive result, you only need basic knowledge of the device itself and microwave electronics, well, in extreme cases, the simplest data search skills on the Internet.

There are a number of reasons why the microwave stopped heating and it's not about parts breakage, for example:

The mains voltage has decreased. The operation of the microwave oven, as well as its heating, can be affected by slight decreases in 20V. As a result, the plate will be heated, but there is no food in the middle of the pot. The issue of a power outage is resolved in one day: you just need to go to the store and buy a power supply.
The network is overloaded. If two powerful devices work from the same outlet at the same time, an overload occurs. This issue can be solved by installing another outlet.
The door is out of order. As a result of the breakage of the latch, the door does not close tightly and the microwave does not heat or weakly heats the food. Here you can try to repair or completely replace the latches.
Wrong mode selection. Very often, after defrosting, they forget to switch back to microwaves. Defrosting does not heat food to the required temperature, and you are about to disassemble the appliance.

Often, the microwave works, but does not heat the food due to the fact that the magnetron is out of order. The next on the list will be a capacitor, a fuse, and a transformer also breaks often. Poorly heated food may be due to the following:

Video (click to play).

the timer or the control unit itself has broken;
due to a breakdown of the transformer and other parts;
the inverter may be defective (this only applies to inverter microwaves).

If you find that the microwave oven turns on but does not heat up and emits an unusual sound (for example, hums), there are 3 explanations for this:

the diode has become unusable. This part does not allow the current to pass in the opposite direction, the current moves only in one direction. If this part fails, the device starts to hum and does not heat up the food;
it's time to change the capacitor. A breakdown of the capacitor leads to the generation of waves and the device hums;
breakdown of the magnetron. A defect in this part can also cause buzzing or humming.

If you decide to find the cause and repair the microwave with your own hands, then keep in mind that this is a dangerous device. Even if the microwave oven is disconnected from the mains, there is a high probability of being hit by a high voltage current, up to 5000 V. If you have doubts and you are not sure of your own knowledge, it is better to show the device to the master, even for just one diagnosis. There is no need to risk your life, because the device is not worth it.

If, nevertheless, you decide to repair the microwave oven with your own hands, then before looking at anything, turn off the device from the network. Be sure to find the instructions, where there are the names of all the parts that are there.

First of all, after removing the cover, you need to make sure that all the fuses are working. If you see that they have turned black or the thread has burned out there, then you just need to replace them. There are often two fuse pieces inside.

When buying a new part, be sure to take the old one (burnt out).To temporarily solve the situation, it is not recommended to make bugs out of the wire. There is a great danger of fire, and the price of a good fuse is no more than 50 rubles.

If the device hums when turned on, there is a possibility that the capacitor has broken. It is easy to check its serviceability: you need to take an ohmmeter and connect it to the part. If everything is in order, then the ohmmeter needle moves. And if it is standing, then the capacitor is out of order, and because of this, the stove is noisy.

Before replacing or checking a capacitor, it must be completely discharged!

If during the operation of the microwave you smell a burning smell or something is cracking inside, after watching this video you will understand what is happening. It shows how you can repair a microwave oven if it sparks.

Often, this device is not checked due to the complexity of this procedure. The easiest way is to buy a new part, but before that, make sure it breaks. You can check with a capacitor that should not be heated. Also, a sign of a diode malfunction may be a hum when turned on and a blown fuse.

If, when checking the device, you did not find any breakdowns, then it is likely that the matter is in the magnetron. The sign by which the failure of the magnetron is determined is a strong noise (hum) during the operation of the device. If the microwave buzzes and does not heat up, then you need to look at the magnetron for cracks or carbon deposits. If the breakage is not visible visually, then check with an ohmmeter. If the magnetron is burnt out, then you need to buy the same one. It must have the same parameters and size.

We have shared with you information on how to act if the microwave works, but does not heat food. It is very important to determine the reason and the problem of why the microwave stopped heating food. Most often, you don't have to look for an answer for a long time: most likely, you used the device incorrectly.
In order for the technique to serve for a long time, you should not do this:

heat food in a metal container (a spoon also applies here);
turn on an empty appliance (no food);
warm eggs;
put containers with lids.

Over time, any equipment can fail due to wear and tear of spare parts. Equipment made in China can quickly break down due to careless assembly, they are used to doing it with high quality only for themselves. If the price of the equipment is rather ridiculous, then remember the expression that the miser pays twice. At the end of the article, we want to give you advice: if your microwave oven is under warranty, then under no circumstances open it, and do not start looking for a breakdown yourself. Trust qualified workers who will carry out diagnostics and carry out the work at the expense of the company.

Even if you feel that you will be able to repair the device yourself, be aware that there is a great danger in any wrong action. The device has the ability to store electricity and can shock you with high voltage. Trust the professionals who can determine the problem even by looking at the device. Your life is much more valuable! Think twice before opening the lid.

Sometimes, putting food to reheat / defrost, we are surprised to learn that the microwave does not heat. Everything works, glowing, spinning, but the food remains cold. What to do? In order not to carry it to repair, you can try to fix the breakdown yourself.

As usual, the reasons for the breakdown of a microwave oven lie in non-observance of the rules of operation. This accounts for most of the problems with household appliances and this case is no exception. Most often, problems begin after:

There is a metal object in the chamber during heating / defrosting / cooking. Most often, this is a spoon or fork that is in the container with food. At the same time, the microwave begins to spark, and after that it starts to be capricious - it sparks, does not heat food.
Another fairly common situation that often leads to breakdowns is heating in a sealed container that is not intended for this. When a certain temperature is reached, the dishes explode, the food scatters around the chamber, clogging the parts of the oven. Rarely does such an incident go without consequences (washing the chamber does not count).

The location of the parts can be like this

Cheap stoves can often break down. They are made in such a way that they are less repaired and more often bought new. And the last obvious reason is wear and tear on parts. If your oven has been in service for a decent number of years, most likely the parts have simply exhausted their working life. As you can see, there are not many technical reasons. Basically, these are erroneous actions of "users". The result is that the microwave does not heat up or does not turn on at all.

To make it easier to repair a microwave oven, let's get acquainted at least in general terms with its device. Most of all we are interested in her "insides".

Microwave device

Generates microwaves magnetron. It is connected to the camera by a rectangular waveguide. In some models, the waveguide is covered by a piece of mica (a gray-brown material that looks like metal), in others, a plastic cover. The magnetron is powered by a transformer, capacitor and diode. There is often a high voltage fuse in the supply circuit to protect the transformer from overload.

There is a fan for cooling the magnetron. Warm air from the magnetron also enters the working chamber through the air duct, which accelerates the heating of food. Steam and excess air are removed from the chamber through special openings that do not allow radiation to pass through.

Microswitches for locking the closed door

To prevent the microwave oven from working with a loosely closed door, interlock microswitches are installed. Until their buttons are pressed (doors are not closed), power is not supplied. When the door is opened, the power circuit breaks instantly. One of the reasons the microwave does not turn on is breakage or sticking of these small parts.

The number of microswitches depends on the model. They can be from 2 to 5 pieces. Some manufacturers also use them in start button and power control circuits. So one of the reasons why the microwave does not heat up may be damage to the microswitch in the power control circuit.

An incandescent lamp is installed in the chamber for lighting. Most often it is located inside the duct.

Operating modes are set from the control panel. It can contain electromechanical switches, or it can be made on the basis of a microprocessor. Digital control again can have options: there can be ordinary buttons that select a mode, or there can be a touch panel. If a trouble happened with the control, it is better not to get into electronics without knowledge and skills. The only thing that can be checked is how well the conductors hold. Everything else - only with the appropriate experience.

There are situations when you put food to warm up, everything seems to work, but even after a long period of time, the temperature of the food is insufficient or completely cold. The reason that the microwave does not heat can be both a serious breakdown and easily removable reasons. Let's start easy:

The microwave oven may not heat well due to low line voltage. For normal operation of the magnetron, 220 V is required. If the voltage is lower, it will work, but the temperature will rise very slowly. The situation is treated by installing a stabilizer. Naturally, it is better at the entrance to a house or apartment, but you can put a small stabilizer only on this equipment.

If the microwave does not heat, you will have to repair it

All other reasons are more serious and must be dealt with separately.

In this section, we will consider the damage that can lead to the fact that the microwave does not heat, although everything is spinning / glowing. To restore performance is more difficult than in the previous paragraph, but not so much that it was impossible to cope with it yourself.

Approximate arrangement of parts in a microwave oven

Sometimes the microwave does not heat up due to a faulty fuse in the magnetron power circuit. It is not present in all models, but it can cause the magnetron to not work. This fuse is sometimes installed openly, but most often in a protective casing (see not the photo), since it stands in a high-voltage circuit.

High-voltage fuses in microwave ovens can be in a protective cover

It consists of a glass flask with metal caps installed at the edges. There is a spring-loaded wire inside, soldered from one end to the contact of the cap. Unlike conventional fuses, the wire does not burn out in this. During long-term operation, the solder heats up and softens, the spring force spreads the contacts.

High voltage fuse structure

If the fuse does not ring and an open circuit is visually visible, there are two ways to solve the problem - replace it or restore the soldering. To restore the high-voltage fuse, you must carefully remove the metal cap on the side from which the wire was soldered, solder it in place. Put the cap back in place and check if it is heating up or not.

There are several damages associated with the magnetron. Let's start again with the simplest thing - weak contacts. The wires from the filament winding of the transformer come to the terminals (to the connector) of the magnetron. They must be removed with difficulty. The heat may have worsened the contact. It can be improved by additionally crimping the contacts with pliers.Sometimes the microwave does not heat up due to damage to the magnetron antenna cap. If the cap is simply blackened or there is a solidified drop of metal on it, but there are no extra holes, it is necessary to clean everything to pure metal, make the surface even. You need to work with fine sandpaper. We achieve the maximum effect - everything should be even / smooth, preferably to a mirror finish. But don't rub the metal to the holes. Upon completion of the work, carefully remove all the dust. The best way to do this is a vacuum cleaner.Antenna cap is damagedIf the cap is melted - as in the photo above, you need to make sure that the magnetron itself is not damaged and there is a vacuum in the middle. To do this, carefully remove the cap and inspect what is under it. If the metal is intact, you can simply replace the cap. If not, you will have to change the magnetron, but at the same time you need to think about the advisability of such a repair - the price of this spare part is high, perhaps you just need to buy a new furnace.How to replace the magnetron cap? It is very difficult to find it on sale - it costs a penny, selling it is unprofitable. There is an option - to grind on a lathe. If this method does not suit you, you can make a suitable size from an old electrolytic capacitor.Old damaged cap and a new one from the capacitorWe select an element of a suitable diameter, cut off the desired piece of the body, carefully drill a hole in the center. All measurements must be perfect. After that, we clean the body with the finest emery paper and polish: the quality of the microwave depends on the conductivity of the cap. We put the finished cap in place, check the work.If you nevertheless decide to replace the magnetron, then take it with you to the store. The new one must match in terms of output power, the antenna must be the same length, and the mounting lugs must also be located in the same place and on the same side. Only then can it be installed in place of the old one.From the side of the chamber, the exit of the waveguide is covered with a plate of mica.Sometimes the microwave does not heat up due to the fact that carbon deposits have formed in it and the waves simply cannot overcome this obstacle. Also, due to such damage during operation, sparks and something similar to lightning or even fire may appear.Darkening is visible on the mica plateIn this case, remove the plate by unscrewing the screws (two to eight pieces). If there are no irreparable changes (no hole), you can try to clean up the blackened place. We take fine sandpaper and gently clean everything off. We carefully remove the dust (you can use a vacuum cleaner), put the plate in place. To make sure everything works, you can turn it upside down.If there is a hole in the plate, it is best to replace it. This spare part is on sale, in stores they know about mica for microwave ovens. Put the new plate in place (you may need to drill holes for the fasteners) and check. If the microwave does not heat the food because of this, everything should work.If the microwave stops heating, everything turns on, buzzes, spins, but the food remains cold, perhaps it's the condenser. We take a tester and test it. We put it in the resistance measurement mode.Microwave condenserIf during measurement it shows an open circuit - it is inoperative, if it shows a small resistance - it is also under replacement, since it is broken. Only if, when touching the capacitor, the arrow "flies away" to infinity - it is in a normal state.Checking a high-voltage diode is not an easy task, therefore most often it is simply replaced. It doesn't cost that much to be a problem. Naturally, the parameters of the new part must match.

An ohmmeter is a necessary device for diagnosing problems in a microwave oven

The instruction manual and user manual are the primary documents that you should refer to when troubleshooting. Often, the manufacturer indicates useful information for the correct diagnosis of malfunctions and their possible elimination with their own hands.

Possible minor malfunctions of microwave ovens and how to fix them:

Make sure the control panel is set to the correct mode (warm-up function).

Use the user manual to set the appropriate command.
Turn on the oven for 1-2 minutes, after putting food or a glass of water in it.
Check the temperature of the food, perhaps the problem was only in the wrong setting.

The oven does not heat food if the home voltage is low:

If devices are also plugged into the outlet with the oven, then disconnect them.
Install an uninterruptible power supply to stabilize the voltage.

Often the door in microwave ovens does not close tightly, and sometimes the latches themselves fail, which in turn start the magnetron.

Solution: replace the latches and close the door tightly.

In other cases, as well as if the microwave buzzes but does not heat up, you should contact a specialist. Repair and replacement of parts under warranty will be free, but in case of an expired warranty period, you will have to pay for the repair from your pocket.

The price, as a rule, consists of the cost of the new part and the services of the master. But you can save a little in this case too, by replacing the defective part yourself.

The table below and illustrative photos will help you cope with the task:

Unscrew the back cover.
Blown fuses stand out from the crowd at once: they are blackened or swollen.
If their appearance is not suspicious, check the resistance.
Remove damaged parts and replace with new ones.

In this case, the microwave oven will no longer have the above problems.

The multiplier capacitor needs to be checked. To do this, you need an ohmmeter:

Small resistance indicates a malfunction.
The motionless arrow indicates the absence of contact.
A slight deviation or mark on the “∞” sign indicates normal operation of the condenser.

Failure of this part is often the reason why the microwave does not heat, but works.

It is worth checking the diode itself. In any case, it is easier and cheaper to purchase a new part than to repair an old one.

We measure the resistance in the same way as described above.
We test the primary winding of the transformer. If it is serviceable, then the voltage should be 220 V. Otherwise, the part must be replaced.

A malfunction of the magnetron can be the reason that the microwave works - but does not heat:

In more than half of the cases, the filament in the magnetron is faulty. To correct the situation, it is enough to simply measure the resistances to diagnose the malfunction.

However, it is easier and simpler to purchase a new magnetron, while it is important to write down all the characteristics and, just in case, take the old part with you.

Do not expect a long and trouble-free service from cheap devices or microwave ovens from little-known manufacturers. Suppose you spend more, but a high-quality branded microwave oven works for a long time, and in case of repair, there is no problem finding a replacement part.

We have analyzed the most common reasons why the microwave stops heating food, although otherwise it functions quite well. Often a problem of this kind can be corrected on your own: you just need to understand the instructions and, in case of malfunction, replace the failed part.The video in this article tells and clearly shows possible solutions to problems with microwave ovens. If you have any questions, I will answer them in the comments. Image - DIY microwave oven repair does not heat

A warm healthy breakfast is the key to a successful day. The presence of a microwave makes our meal pleasant, since it is not always possible to eat food in the heat of the heat.

But what if there are technical problems with the microwave oven? The microwave does not heat up, but it works - what should I do? DIY repair is possible, and you need to look for a way out of the situation, since not everyone wants to allocate an amount for the purchase of a new device. In order to understand whether the help of a master is required, it is necessary to understand the reasons for such a strange behavior of the microwave oven. Let's get acquainted with all the nuances of this case.

Everyone loves to have a hearty meal. The temperature state of the dish is also a culinary nuance, but it so happens that the microwave refuses to do its job. This problem can be caused by the following reasons:

The mains voltage is insufficient for the supply.
Broken switch on or inside the device.
The mains fuse is out of order.
The housing contains a high voltage fuse. It can also fail.
The fuse inside the transformer has blown.
There is a problem inside the doubler regarding the diode.
There is a problem inside the doubler regarding the capacitor.
The transformer has ceased to perform its function, therefore the voltage supply to the control panel is cut off.
The through-line capacitor “flew”.
The electromagnetic lamp itself stopped working. It is also called "magnetron".

Read also: DIY peugeot 206 beam repair

Important! Sometimes the cause of various malfunctions can be the layers of fat on the inner walls of the microwave. In order to extend its operational life, the microwave oven must be kept clean and tidy. Read in another article on our website about how to wash your own microwave from fat.

You need to arm yourself with instructions and figure out how exactly the microwave oven works. Many manuals explain in an accessible language why the microwave does not heat up, but it works, what to do in such situations. In this manual, it is very easy to find the answer to the question of interest and take any measures with its help.

What to do next to repair the microwave oven with your own hands if it does not heat:

First you need to measure the mains voltage. The slightest deviation will directly affect the quality of the device.
The next step is to de-energize the microwave. Safety measures are the basics of school physics. We take the "tshka" in our hands, turn on the ohmmeter and we need to further analyze the operation of the switch, which is located on the oven door. Now you need to remove the cover, getting rid of the screws that hold it.
Then you need to deal with the mains fuse. It is not difficult to visually determine the presence of a defect: if the wire is black, then it has burned out, but it is better to play it safe and walk with a multimeter here too.
Now it is necessary to check the high-voltage fuse located in the casing with the same ohmmeter. If the device shows at least some resistance, then things are not so bad.
We are looking for a fuse on the transformer inside the microwave and check it in the same way: with an ohmmeter and visually.
Next, you have to climb into the multiplier and check the operation of the diode and capacitor. "Tsshka" will help to determine if the condender is in good working order, even though it operates on alternating current:
- If all is well, the tester needle will go to infinity, as the capacitor will “intercept” a small charge from your tester.
- If the arrow does not move, then the contacts are broken.

Important! It is also a bad sign that there is resistance - this means that the capacitor has experienced a breakdown. It is easier to replace the diode with a new one right away to avoid the trouble of checking. A new diode costs ridiculous money.

Is everything in order? The microwave turns on, but does not heat up, what's the problem? We need to get even deeper!

Important! If, after all, you have not been able to find the cause, or if the microwave oven cannot be repaired at all, you will have to consider buying a new appliance.In order to shorten your searches, we've compiled a list of the best microwave ovens.

Let's delve into the work of radio amateurs and test the passages for the filter capacitor, which are located on the body of the electromagnetic lamp.

Before starting the test, discharge the conductors with an electrical screwdriver with an insulated handle. You just need to short-circuit the outputs to ground one by one. We install one probe of the "tshki" at the outlet of the container, and the second - we ground it to the metal body:

Zero resistance, which an ohmmeter can show, will mean that everything is fine.
If the resistance takes on any values, you will have to replace the old part with a new identical one.

Then it is necessary to check the contacts of the plates for breakdown with the same tester. Normal resistance between contacts takes values in the region of one tenth of Ohm.

Again we take our favorite "tshka" and climb into the transformer winding. The voltage on the primary winding during the operation of the microwave must correspond to 220 Volts.

A magnetron independently generates electromagnetic waves with a specific frequency when a magnetic field and an electric current interact. Visually assess the quality of the soldering of the filter inductance contacts and the integrity of the installed terminals that power the magnetron and feed-through capacitors.

Is it the terminals or broken contacts? A soldering iron and your hands will help. The elimination of such problems should not raise questions.

Now, using a measuring device, you need to check the resistance of the filament of the electromagnetic lamp. The value should vary within 2-3 ohms. If everything is in order, but the microwave still does not work, then the problem is in the magnetron itself.

Important! Do not repair the high-power lamp yourself. It is better to use the services of a qualified specialist.

There is also an option with the purchase of a new magnetron. To do this, you need to find and write down in a notebook all its technical parameters: output power, cathode voltage, current and voltage of the filament, anode current. It is best to purchase the device in a workshop.

Important! What to do if everyday food is already boring and does not cause a pleasant feeling of satiety? To help you enjoy tasty and healthy food, we have collected the best recipes for dishes cooked in the microwave.