DIY microwave repair no heating

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:

1. 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.
2. 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.
3. 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.
4. 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:

• 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 avaricious 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 appliance has the ability to store electricity and can shock you with high voltage. Trust the professionals who can diagnose the problem even by looking at the device. Your life is much more valuable! Think twice before opening the lid.

Many of us have forgotten about various stoves, hobs and completely trust the process of cooking microwave ovens. And this is not surprising at all: microwave ovens take up little space, have a rich set of different functions and significantly save time. Naturally, we are very upset when our microwave breaks down. The reasons for the breakdown and malfunction can be different. Consider what breaks down most often in a microwave oven. Often, if a microwave oven breaks down, it is necessary to contact a specialized master. After all, this is not the simplest device, so the repair is rather complicated. But in fact, the design of a microwave oven is elementary and includes only a few basic elements. If you first familiarize yourself with frequent breakdowns, then repairing the microwave on your own will not be difficult.

Although the design of a microwave oven contains a lot of elements, most of them do not play a special functional role. To repair this device, you only need to know the basic elements of the circuit that ensure its operation. Among them:

1. Magnetron.
2. Transformer.
3. High voltage fuse.
4. Rectifier diode.
5. Capacitor.
6. Control block.

Arrangement of elements in the microwave

It is easy to distinguish them, because outwardly the design is not very complex. The magnetron is always installed in the middle, directed towards the food warming unit. The transformer is located under it, representing a massive box with a protruding coil. The capacitor, diode and fuse are located to the right of it, and the control unit is often located near the input panel.

When the device is turned on, a voltage of 220 V is supplied to the transformer. Passing through the primary and secondary windings, a current of 2 kV is already flowing out of the element. Further, the negative half-wave goes to the diode, and the positive one charges the capacitor, which again leads to a twofold increase in voltage. After that, the generation of microwaves by means of a magnetron begins. The power of the magnetron is regulated by the control unit.

Therefore, in the event of a breakdown, it is worth paying attention to these elements. They carry the greatest load, so they are often the problem.

When disassembling the microwave, be sure to disconnect it from the mains.

Search for breakage in a microwave oven is based on "symptoms". This allows you to gradually eliminate possible causes and find the real one. So, if the oven does not turn on at all, then it is worth checking the following points:

• The integrity of the power cord.
• Door position and closing system.
• Mains fuse and thermal relay status.

In the first case, the situation is elementary - there is no power supply due to damage to the power cord. A similar situation occurs when the outlet is damaged or overloaded. In this case, it is enough to replace this element, everything is in order with the microwave itself.

Next, it is worth checking the operation and position of the door. The fact is that the operation of a microwave oven when the door is open is dangerous for others. Therefore, the design provides for the possibility of operation only when it is completely closed. If a latch, a locking system or a checking element is broken on the door, the protection system will not allow the device to start.

The last points also concern the protective systems of the oven. The fuse prevents damage to the device due to power surges, and the thermal relay provides a complete shutdown of the system when the door is open. Both can fail, it is quite easy to replace them.

It is also worth checking the voltage in the network and the number of devices connected to the outlet. The microwave oven is very demanding on power supply, therefore its slight deviations can interfere with the operation of the appliance.

Procedure if there is no heating Fuse faults

Most models suffer from common problems and have similar, typical faults. For example, if the microwave works, but does not heat, then this indicates a malfunction of the capacitor, diode or magnetron. To repair a microwave oven yourself, you will need a simple set of tools: pliers, wire cutters, a screwdriver, an adjustable wrench and a five-spanner wrench, as well as a soldering iron with the necessary equipment.

When repairing a microwave microwave yourself, you should remember about safety measures. The two most important hazards in microwave oven repairs are high voltage in oven components and microwave radiation. Do not turn it on if the door is defectively locked or the mesh on the viewing window is damaged. Do not make independent holes in the case and introduce any conductive objects into the units and elements of the furnace. Never touch internal parts and assemblies while the microwave is in operation.Be sure to use a tester or other electrical meter to measure AC and DC current.

If the above reasons are not confirmed, then you need to disassemble the device for troubleshooting. Before that, be sure to turn off the oven from the network and wait a couple of minutes.

Fuse

What should you look for when searching for breakdowns? There are several basic elements that often fail:

1. Circuit breakers.
2. Capacitor.
3. Diode.
4. Transformer.
5. Magnetron.

Photo of a microwave condenser

These elements are directly involved in the operation of the device and were mentioned earlier. First you need to check the health of the fuses. Their breakage can be seen immediately, because during combustion, the conductor inside is destroyed. If this did not happen, then it is worth looking further.

For further verification, you need to take a multimeter, because outwardly it is extremely difficult to find a breakdown on the remaining parts. To check the capacitor, you need to switch the device to ohmmeter mode, and then connect it to the part. If there is no resistance, then the part must be replaced.

High voltage diode

It is impossible to check the high-voltage diode with a tester. It is recommended to replace it in case of breakage of other parts, because often the blow falls on it. It can be checked in a slightly different way - by connecting it to the network on the way to the light bulb. If the light is weak or blinking, then the part is working properly. If it burns brightly or does not turn on at all, then the diode must be replaced.

Next, the transformer is checked.

Photo of a microwave transformer

It is important to observe safety precautions, because

Photo of microwave magnetron

this element is able to hold a charge for a long time. It will take several minutes to discharge a serviceable transformer, and if the discharge resistor breaks down, it will take much longer. It is worth discharging it on the case or not touching it at all if there is no experience with such a technique.

Next, the transformer windings are checked. It is necessary to remove the terminals and check the terminals of the device one by one with an ohmmeter. First, the primary winding is checked, for which the rate varies from 2 to 4.5 ohms. For the secondary winding, the limits are 140 and 350 ohms. It is also worth checking the filament winding by connecting the terminals leading to the magnetron to the multimeter. The norm here varies from 3.5 to 8 ohms.

All previous tests have failed, then the problem may lie in the magnetron.

To test the magnetron, just connect the tester to its power terminals. The tester switches to ohmmeter mode. If the resistance is 2-3 ohms, then this means a breakdown of the device. The situation is the same if the tester reads infinity. In both cases, the device must be replaced.

These items are the most common culprits in microwave oven breakdowns. However, the failure of the device is often associated with other malfunctions, such as problems with the electronic control unit, timer and other electronic parts. Here, simple checks with a multimeter will not help; the help of a qualified technician is needed. Although it is much easier to simply replace a part if you are sure that it is broken.

There are frequent cases of breakage associated with the destruction of the cap on the magnetron. The thin aluminum body simply cannot withstand stress and is destroyed by microwave waves. This problem often occurs in older devices that are more than a few years old. The obvious symptoms in this case are noise and sparks during the operation of the device.

To check, it is enough to remove the transformer, because the cap is located towards the food chamber. If the cap is destroyed, then there are 2 options:

• Cap replacement.
• Flip the cap.

The first option is a priority, it is enough to order a replacement or return the magnetron for repair.The second option is considered a temporary alternative that allows you to extend the life of the device indefinitely. It is enough just to rotate the cap 180 degrees around the axis, because the load falls on only one half.

Repairing a microwave oven is a feasible task for a novice electrician. If the problem lies in the breakdown of one of the constituent elements of the furnace, then the simplest and correct solution is to replace it. The bottom line is that most of the parts of this device cannot be repaired, but only completely replaced with a new one. This especially applies to fuses, diodes and capacitors - the main reasons for the failure of the device.

Parts replacement is carried out in several steps:

1. The microwave is disconnected from the network.
2. The transformer is discharged (5 minutes).
3. The terminals are disconnected from the defective part, it is removed.
4. A workable part is connected to the same place.

There are two important factors to consider when replacing a part. The first is schema compliance. It is important to remember that each part has its own characteristics, selected for the performance of the entire electrical circuit. If, after replacement, this nuance is not taken into account, then this leads to new breakdowns. This is especially true for the transformer and capacitor.

The second important factor is the connection of the part. It is necessary to connect the replacement correctly, keeping the previous arrangement of the terminals. Reconnecting the device in reverse order can damage it, as well as several other parts in the system.

This will restore your microwave in most cases. If the breakdown is related to the electronic part of the device, then you should contact the professionals. This will ensure quality repairs and prolong the operation of the device for a long time.

The most common malfunction is the failure of the waveguide cover in the microwave oven chamber. This is caused by splashes from cooking. This starts sparking between the magnetron antenna and the protective cover. Untimely removal of burnt products leads to local burnout of the lid and to complete destruction.

Local burnout of the lid mica plate can be removed with alcohol or solvent 646. It is enough to gently wipe the burnout area.

Burning out mica

If the mica plate of the lid is clearly in poor condition, is greasy or begins to paint, then it should be replaced. Removing the diffuser plate is a snap. This can be done using an ordinary sharpened knife. Usually, the mica plate is attached with a self-tapping screw or rivets. Carefully place the old plate on the new template and cut out a new one. The best way to do this is with a knife - you can break the mica with scissors. We make holes in the new plate with a sharp screwdriver and process the edges of the fields of the plate with sandpaper. We install the new plate in place of the old one.

The question often arises, how to replace mica for microwave ovens? For these purposes, any dielectric with a similar dielectric constant is suitable. For example, PTFE or Teflon.

Common breakdowns in a microwave oven are also malfunctions associated with other elements of the oven. For example, such as the keyboard of the oven control unit, the microwave oven electronic control unit and the dissector. Less often, the high-voltage capacitor and transformer, the microwave waveguide plug and the rotating pan fail. The power supply and magnetron of the microwave oven are subject to wear and tear.

Knowing how to troubleshoot microwave ovens can save you significant repair costs. However, if you do not know how to repair the microwave yourself, then it is best to contact a specialist. Specialized service centers will help you to repair the microwave microwave. In addition, watch the video on microwave repair, perhaps there is exactly that breakdown that will help you fix your beloved household assistant.