DIY eyelid TV repair for beginners

In detail: do-it-yourself eyelid TV repair for beginners from a real master for the site my.housecope.com.

"There is a contact where it should not be (short circuit) and there is no contact where it should be (open circuit)."

I switched it on again by connecting a 200 W incandescent lamp instead of a fuse. I have such a lamp at home in a separate socket, from which there are wires with clips - crocodiles. This llama turns on as an indicator and current limiter in the circuit when setting up a device powered by 220 volts. If there is a short circuit in the device, in other words, its resistance is zero, the lamp lights up, as if it was connected directly to 220 volts. If the device is operating normally, then the lamp passes through itself the current necessary for the operation of the device, since in a cold state the resistance of the lamp filament is small.

The graph of the dependence of the lamp current on voltage, for example, lamps from lanterns

In this case, the lamp lit up, which signaled that there was a short circuit somewhere in the TV. In such cases, I usually start looking for a malfunction from the power supply. True, in this case, I first removed the posistor, its resistance corresponded to the norm. After the diode bridge was removed, it also turned out to be working. Then it was the turn to check the output transistor at the power supply microcircuit, so that the parallel soldered parts do not affect the measurement results, it was also soldered out.

Transistors are tested as follows: as you know, in simple terms, a bipolar transistor is 2 connected diodes, either cathodes or anodes, and can be easily called in the diode test mode by connecting, depending on the structure, either a red or a black tester probe to the base. The second probe touches in turn the collector and the emitter, if the tester displays the numbers about 800 - 900 in both cases, then the transistor is intact. True, it will not be superfluous to also check it in other directions, in order to be completely sure that it is serviceable.

Video (click to play).

The output transistor of this microcircuit Base - Emitter - Collector everyone called each other shortly in all directions. The cause of the short circuit was found and eliminated by replacing the microcircuit.

Also, several resistors were checked, (turned out to be intact) and replaced, just in case, on the advice of 3 electrolytic capacitors from the forum. All parts were bought for 100 rubles. After the microcircuit, diode bridge and posistor were soldered in place, the TV was turned on with a 200 W lamp connected instead of a fuse. Everything worked! But there was another problem, the image was dominated by red, which was also solved on the advice from the forum by adjusting the contour in 15 minutes.

Outcome: a working TV for 100 rubles, while the cost of repairing a TV in a TV workshop in our city starts from 700 rubles. Successful repairs to everyone! AKV.

You have visited the site "Telemasterskaya", the main focus, assistance in the repair of electronic equipment for novice radio amateurs, as well as for those who are carried away by electronics and are taking only the first steps in this direction.

However, it will also be useful for more "advanced" repairmen, since modern electronics is quite complicated and often even a good specialist spends a lot of time diagnosing a malfunction, and the site will help remind the main malfunctions of TVs or suggest solutions to new ones.

For novice radio amateurs on the site there are special headings “Let us know the world of electronics”, “Beginner radio amateurs” with published materials from which you need to start acquaintance with the fascinating world of electronics, these are radio components and their device, spare parts for repair, and where you can get them. There are also materials on the tools necessary for the repair (soldering irons, solder, etc.) In the "Devices" section, you can find information on the devices (oscilloscopes, millimeters) necessary to diagnose faults in household radio electronic equipment.

The quality of the image directly depends on the quality of the received signal, therefore, the topic of an antenna for a TV with reception of both analog and digital signals is necessarily touched upon. The device of antennas, what they are, which ones are better.

With the advent of "digital", video tape recorders very quickly became a thing of the past, so repair of DVD players and music centers will be considered.

The topic of the repair of automotive electronics will be touched upon, since there are also enough problems in this area. Car radios - cassette, disc, receivers, multimedia, they also break down. In addition, it is possible to revise old, but serviceable tape recorders and with such an upgrade, we extend the life of car radio electronics.

Image - DIY eyelid TV repair for beginners

We will not ignore the news in the field of television, although it is rather difficult to follow them, everything is changing so quickly in this area. Since new TVs open up new opportunities, therefore, articles will be published on topics related to digital television (cable, satellite, digital terrestrial television DVB-T2).

It is no secret that a breakdown of a television receiver can ruin the mood of any owner. The question arises, where to look for a good master, do you need to take the device to a service center? You need to spend your time on this, and what is important - money. But, before calling the master, if you have basic knowledge of electrical engineering and know how to hold a screwdriver and a soldering iron in your hands, then repairing the TV with your own hands in some cases is still possible.

Modern LCD TVs have become more compact and easier to repair. Of course, there are breakdowns that are difficult to detect without special diagnostic equipment. But most often there are malfunctions that can be detected even visually, for example, swollen capacitors... With such a breakdown, it is enough to evaporate them and replace them with new ones with the same parameters.

All TV sets are the same in their structure and consist of a power supply unit (PSU), a motherboard and an LCD backlight module (lamps are used) or LED (LEDs are used). It is not worth repairing the motherboard on your own, but the power supply unit and screen backlight lamps are quite possible.

As already mentioned, the design and principle of operation of LED and LCD TVs, regardless of the manufacturer, are the same. Of course, there are some differences, but they do not play a significant role in the diagnosis of faults. Often, in the event of a problem with the power supply, the LCD TV does not turn on at all, while there is no indication, or it turns on for a while and turns off spontaneously. Using an example, the repair of a DAEWOO LCD power supply unit (can be applied to plasma) is considered, which is not much different from repairing an LG TV, as well as Toshiba, Sonya, Rubin, Horizon and similar models.

First of all, before you repair the TV, you need to remove the back panel of the device with a screwdriver by unscrewing the screws. On some models, the rear wall may be latches installedwhich must be handled with care so as not to break them.
After removing the cover, you will see the power supply unit, consisting of several modules on the left, and the motherboard on the right.
On the power supply board you can see 3 transformers: the bottom one is the mains rectifier choke, the top one on the left (large) feeds the inverter, and on the right is the standby power supply transformer. You need to start checking with it, since it turns on the standby mode of the TV receiver.
Duty transformer when the device is connected to the network, it should give out a voltage of 5 V. In order to correctly find the wire on which you need to measure the voltage, you can use the diagram, or you can see the markings on the case. In this case, opposite the required contact is written - 5 V.

Measurement is taken first open circuitby connecting one probe to the found contact, and the other to the cathode of the diode on the radiator. In this case, there is no break.

Further, one tester probe can be attached to the body of the device, the other to the previously selected contact, and measure the voltage, having previously connected the telly to the network. In this case, the device shows 1.5 V, instead of the required 5 V. Such readings of the transformer indicate that it is working, but not at full strength. The reason may be dry condenserlocated below, or swollen - above the transformer.

To remove the parts that have become unusable, it is necessary to remove the power supply board. To do this, first disconnect all wires and the matrix cable coming from the inverter and the system board. So that in the future, after repairing the power supply, you do not get confused where what is connected, you can take a picture of them before disconnecting the wires and loops.

Now you can remove the entire LCD TV power supply by unscrewing the 4 screws. After removing it, it is very important discharge all capacitorsto avoid electric shock.

We solder the defective capacitors and replace them with new ones, observing the polarity.

The assembly of the device takes place in the reverse order: the board is screwed into place, all connectors and cables are connected, the rear panel of the unit is closed.

We again measure the voltage on the transformer of the TV's power supply (the device should turn on) and see that it has become 5v. When you unfold the repaired TV receiver, you will see that it works.

As you can see from the review presented above, repairing TV power supplies with your own hands is not such an overwhelming task. Following this description, you can also repair plasma TVs.

Do-it-yourself TV repair with a kinescope, for example, such as: Rubin, Horizon, Sharp 2002sc, LG TVs, as well as repair of the Vityaz TV, begins with checking the power supply unit for operability (this is done if the unit does not turn on). It is checked using incandescent bulbs for 220 V and a power of 60-100 W. But before that, be sure to disconnect the load, namely the horizontal output stage (SR) - connect a lamp instead. The CP voltage ranges from 110 to 150 V, depending on the size of the tube. Must be found in the secondary circuit SR filter capacitor (its values can be from 47 to 220 microfarads and 160 - 200 V), which stands behind the SR power rectifier.

To simulate the load, you need to connect a lamp in parallel to it. To remove the load, for example, in the popular Sharp 2002sc model, it is necessary to find and unsolder the inductor (located after the capacitor), the fuse and the limiting resistance through which the CP stage receives power.

Now you need to connect the power supply to the power supply unit, and measure the voltage under load. The voltage should be between 110 and 130 V if the CRT has a diagonal of 21 to 25 inches (as in the 2002sc model). With a diagonal of 25-29 inches - 130-150 V, respectively. If the values are too high, then it will be necessary to check the feedback circuit and the power supply circuit (primary).

It should be noted that electrolytes dry out during prolonged operation and lose capacity, which, in turn, affects the stability of the module and contributes to an increase in voltage.

When the voltage is too low it is necessary to test the secondary circuits to exclude leaks and short circuits.After that, the diodes for the protection of the power supply of the SR and the diodes for the power supply of the vertical scan are checked. If you are convinced that the power supply unit is working properly, then you need to disconnect the lamp and solder all the parts back. This check can also come in handy when doing DIY Philips TV repairs.

Another common breakdown of the TV that can be eliminated is the burnout of the backlight lamp. In this case, the TV receiver, after switching on, flashes the indicator several times and does not turn on... This means that after self-diagnosis, the device notices a malfunction, after which the protection is triggered. That is why there is no image on the screen.

For example, a Sharp LSD TV receiver with this malfunction was taken, although in this way it is possible to repair Samsung TVs, Sony Trinitron, Rubin, Horizon, etc.

Next, you need to be careful disconnect loops from the matrix.

The next step is to detach the control panel from the case. You do not need to remove it, you will still need it to turn on the device.

The remaining loops also need to be disconnected. Then it is necessary to remove the housing on which the electronic boards are fixed.

Before removing the matrix, unscrew front frame... We remove the matrix itself and filters, snap off the side mounts.

We connect the power and hold down a few keys to enter service menu... This will keep the lamps on for a while.

The figure below shows that after turning on the lamps, the 5th from the top turned out to be inoperative. Disconnect it and replace it with a new one - now all the lamps are on when checking.

The assembly takes place in the reverse order.

After that, you need to turn on the TV receiver and enter the service menu for reset lamp error counter... If this is not done, the device will not work. Entering the menu, you need to find the corresponding line and reset by selecting ok. Now the repair of the LCD TV set is finished. Tests show that the unit is operating normally.

Thus, you can repair the Philips and LG TV with your own hands, and other LCD panels, as well as devices with LED backlight (LED). Owners of the latter type of devices should read the article on repairing LED backlighting, where the whole process is described in detail using the example of an LG TV.

Among the typical and simple reasons that the TV set does not turn on, there may be a remote control or a lack of signal from the antenna cable.

If the TV does not turn on with the remote control, first, you need to make sure the batteries are good. If they are shrunken, replace them. Often the TV set cannot turn on due to contamination of contacts under the buttons. To do this, you can disassemble it yourself, and clean the contacts with a soft cloth from accumulated dirt. If your remote control has been dropped, it is possible damage to the quartz emitter... In this case, it must be replaced. Well, if you filled the remote control with water or some other liquid, and it did not work after disassembling and drying, then it will have to be replaced with a new one.

You can learn more about fixing the remote control in the following video or article.

When repairing TVs LG, Sharp with LCD, Rubin, Horizon with the same screens, a situation often arises when it does not turn on when the device is in good working order. It turns out that the reason may be no TV signal in the antenna cable. This happens due to the operation of the noise suppression protection (in Rubin TVs, they began to install it not so long ago), and the unit goes into standby mode. Therefore, if you find your TV set inoperative, you should not panic, but you need to check the presence of a signal from the transmitting station.

In conclusion, we can say that when you decide to repair a TV set yourself, you should soberly assess your abilities and knowledge in this matter.If you do not feel confident, then it is better to entrust this matter to a telemaster, especially since nobody canceled 220 V, and ignorance of basic safety rules can entail unpleasant consequences.

Without video and audio equipment, few people can imagine a full-fledged home, and it is precisely because of regular and intensive use that this type of equipment is most often subject to breakdowns. Repair of TVs can be done at home, if you call a master, or do all the work yourself.

Before starting repair work, you should determine what exactly broke in the TV. In any case, this will greatly facilitate both the independent repair process and the clarification of the essence of the problem to the TV technician.

Photo - Samsung design

The main types of faults:

The device does not turn on. In both CRT models and more modern LCD TVs, a malfunction occurs due to a blown fuse. But in different devices, it can be represented by different details. At the same time, the problem may be a burnt out diode bridge; Photo - kinescope
The potential of imported and domestic projection TVs is very often lost. A posistor is responsible for this function;
Breakdown of plasma monitors. These include color changes, swings, interference, or dark (light) streaks on color TVs during broadcast;
However, sometimes problems with turning on or operating certain functions are due to a faulty power cord or outlet.

Of all these troubles, the most difficult to fix is screen breakage. For example, if light reflections appear on the monitor after a shock or water ingress on the matrix, then it is better to immediately take the device to a service center, where it can be repaired under warranty.

Photos - details

But most of the repair work can be done easily with your own hands. Let's consider in order how to carry out urgent repair of home LCD and LED TVs Thomson (Thomson), Sharp (Sharp), Samsung, Panasonic (Panasonic) and other models:

The difference between the above types of TVs lies in the different backlighting, but in principle, their operating schemes are very similar. In LSD TVs, the monitor is illuminated by fluorescent lamps, and in LED - by LEDs. Therefore, if the monitor does not turn on, you immediately need to check whether the backlight is receiving power;
Regardless of the brand, the back panel is removed. It is screwed to the base with screws. After that, you need to remove the network power wires from the matrix (first unplug the device from the outlet); Photo - rear panel
To check their performance, you need to connect the most ordinary lamp to the contacts. Most often used at 100 watts;
It should be noted that modern Toshiba (Toshiba), Sony (Sony), Philips (Philips) can connect several backlight sources to the circuit, so you will need to check each one separately; Photo - matrix
For testing, the matrix is removed, a lamp is connected to the contacts and the power wire is connected to the network. If it is working properly, then the lamp will light up. If not, then you will need to replace the cable or repair individual threads.

In addition, a certain area of the backlight may burn out.

In different models of television equipment, the lamp is replaced in different ways. For example, for many Daewoo, Akai and Hitachi TVs, to dismantle a burned-out lamp, you will need to remove the matrix from the panel and reinstall the element on it. At the same time, for some Rolsen and Funai, it will be possible to change a burning light bulb or diode without dismantling it. Depending on the design, you will need to bend (unsolder) the contacts, remove the gasket and carefully remove the burnt element from the case. In its place, a completely similar lamp is installed, both in terms of parameters and dimensions.

Photo - LCD monitor device

Many Chinese models of television equipment - CTV, VAO, BBK, during disassembly you can see light stripes on the matrix.They indicate a breakdown of this particular element. Due to some external factors, the part stopped working and oxidized. In this case, you need to select an element that is identical in terms of performance and install it in the place of the faulty one.

Unlike old stationary CRT or portable models, plasma and ED versions are very rarely repairable if the screen breaks. This is a very time-consuming process, so not even all professional workshops undertake such work. In most cases, if the monitor is cracked, it will be cheaper and easier to buy a new TV set than to repair the old one.

Video: PHILIPS TV repair

Despite the total use of plasma, many owners still have more outdated CRT TVs (for example, Vityaz, Elt, Rubin, Horizon, JVC). Step-by-step instructions on how to carry out repair work on electron beam models:Tips on how to check the TV posistor may be different, but any professional telemaster will recommend that you measure the resistance between its contacts. The part has four of them, that is, two pairs. For one honey, the resistance can be up to 600 ohms, while the other's resistance is in the range of 1-5 ohms. But this is only a theoretical check; for a more accurate diagnosis, you will have to solder the posistor.In addition, capacitors and transistors often burn out in CRT TVs. They can even be diagnosed visually. They swell or change color on the board. If you see that the capacitor is blackened or cracked, then it must be replaced with a working analogue.DIY TV repairTV repair after a thunderstorm Hello everyone! Summer is a good time, but natural phenomena, such as thunder and lightning, sometimes cause a lot of trouble and expense for users of electronic equipment. This article is just devoted to such troubles, or rather the repair of the TV, which has become a victim of the elements. As usual, we will put this situation on the shelves using a specific example. So, …Repair of the Daewoo KR29M5-MT TV Hello everyone! In this article I will tell you about the repair of the Daewoo TV, model KR29M5-MT, which I made. On my site there are many articles on a similar topic, but this case, I think, is worthy of a separate discussion, since several breakdowns occurred on one TV at once, independent of each other. Since this case ...TV repair, fuse blows Hello everyone! It often happens that the TV suddenly stops working. One gets the impression that they just turned off the light. But in fact - it's a blown fuse in the TV. Moreover, if this fuse is replaced, it immediately flies out again. So what could be the reason for this behavior of our television receiver? The reasons may be ...TV power supply repair Hello everyone! Chinese-made TVs have firmly entered our life, attracting us with their rather low cost. But, like other equipment, they also tend to break. In this article we will analyze one of these "masterpieces" and try to repair the TV with our own hands. Chinese TVs, for the most part, are structurally very similar and differ ...Repair of a CRT TV LG Hello everyone! This article will focus on the simplest, but at the same time the most common, malfunctions of LG CRT TVs with a diagonal of 29 inches (72 cm). Such malfunctions can be dealt with with the skills of working with a soldering iron, as well as with normal vision. No more skills, except for holding a screwdriver in your hands, in this ...Repair of TVs Hello everyone! In this article, I want to tell you about the do-it-yourself TV repair method, or rather, what you need to look at first in case of a particular breakdown. This method is based on personal experience and the experience of most telemasters.So, for example, a TV comes to you for repair, in which a line transistor has failed. ...Hello everyone! When repairing various electronic equipment, the primary task is to determine the malfunction. Often, the search for the cause of the failure of a particular device takes much longer than its elimination. This article suggests some technique for troubleshooting modern TVs. When there are situations when the TV does not show any signs of life, I try to adhere to this particular method ...Fixing a CRT TV Nowadays, the time of mass distribution of disposable equipment, the repair of CRT TVs looks like an anachronism. But, nevertheless, such devices, released decades ago, continue to reliably serve their owners, delighting them with natural color rendering and a certain inviolability of life. Unfortunately, there are no eternal things, and sometimes the owners of rarities have to get acquainted with such an area of knowledge as ...Hello everyone! We are all upset and even nervous when our TV set breaks down, because now we have to look for a good TV technician or service center, deliver our device to the place of repair. Another important point is a waste of time, effort and, most unpleasant, money. What if you try it yourself? In this article we will look at how you can produce ...Breakdown may occur at any stage of TV operation. In this case, immediate repairs are required, which can be done on their own. We will discuss how to do this further.To determine how to repair LCD TVs and other models, you first need to establish the cause of the breakdown. To do this, you need the following hardware:

tester or multimeter - to determine voltages at special (control) points, measure the values of resistors and capacitors, continuity of circuits and parts (coils, transformers, diodes, etc.);

amplifier - to determine the location of the loss of the audio signal;

oscilloscope- to match signals at certain points with the TV circuit. It is used at home quite rarely, since not everyone knows how to work with it.

Regardless of the malfunction, you will need the following devices for repairing TVs:

screwdrivers of different sizes (straight, cross-shaped, rarely asterisks);

"Hexagons" - quite rare, but needed;

pliers, wire cutters, etc.

soldering iron (25-60 watts) with rosin and tin;

hair dryer or soldering station - for modern flat screen models.

schematic diagram of the TV unit (can be found on the global network). For example, a diagram of LCD devices looks like this:

A special troubleshooting technique has been developed for beginners, which will help to navigate during repairs. The table provides a description of the main malfunctions and instructions in which unit to inspect and repair the TV.Note that if during a visual review you find darkening on the board, carbon deposits, swelling or rupture of parts, then you cannot immediately change the damaged elements. A burned-out component can be a sign of a short circuit, and the reason will be in a completely different direction. Image - DIY eyelid TV repair for beginners

As indicated in the table, the cause of the breakdown may be in the power supply, the power button and the cord. The wire and the button are easily called by the tester, and the serviceability of the button must be determined in the off and on state. The situation is more complicated with the power supply unit. If, during inspection, damaged parts are revealed, it is not a fact that after replacing them everything will work. For example, capacitors can swell from time, overvoltage or short circuit in a completely different circuit (secondary).

In any case, you need to ring all the details of the power supply unit. We carry out in the following sequence:

If the “condender” is swollen, the posistor is cracked or another obvious defect is visible, it is necessary to evaporate this element and clean the carbon deposits or electrolyte.
We start checking with fuse 2 and posistor 3. Then we call the diode bridge, resistors, transistors and a microcircuit (if a high-voltage stabilizer is installed).
If everything is in order, install the new elements instead of the old ones.

When replacing parts, especially transistors and microcircuits, be sure to install gaskets (mica or rubber) if they were installed under the housings of these elements. They serve to isolate the components from the case.

There are two options for the location of the power supply unit in such devices:

Interior... It can be located in such a place that sometimes it is necessary to disassemble the entire TV monitor. For example, many Chinese models do not have screws securing the cover. To repair them, you need to pry off the plastic case with a flat tool (screwdriver) and remove the screen with the video driver, followed by the metal casing. By removing (unscrewing) it, you will reach the power supply unit.
External... It is more convenient for repairs, since there is no need to "climb" into the monitor itself.

All these PSUs are similar in principle to the power supply unit of a conventional CRT apparatus, and the method for finding breakdowns is the same. The only difference is in the element base and output voltages. Consequently, the repair of plasma TVs and LCD devices in terms of power supply is no different from the above.

This indicates a malfunction in the backlight circuit. There are two reasons for this:

The fixtures (lamps or LEDs) are damaged.
No power is supplied to the backlight (backlight generator, transformer, transistors).

If the LCD has a lamp backlight, then the others have LED backlighting.

First option

LCD devices have from 1 to 10 lamps. Rarely do all the lamps burn out at once. In the first case, the lamp itself may be faulty. As a rule, TVs with a different technology have LED strips installed. In many models, they are in series, and the combustion of one of the LEDs leads to the extinguishing of the entire screen.

Repair of LCDs and other TVs is performed as follows:

Step 1... Open the case.

Step 2... Remove the driver and power supply boards (they can be located in a metal casing).

Step 3. Disassemble the screen part. To do this, you need to remove one or two metal covers and (if any) protective film.

Step 4... Find backlights or LED strips.

Step 5... Replace those that do not burn. It does not interfere with pre-visually and with a tester to check the contacts in the lamps or the diode tape for an open.

Second option

If you have the second case, and all the lamps are off, most likely the matter is in the power supply of the backlight. In the LCD equipment, a high-voltage converter is used, made according to a transformer circuit. Defective parts (microcircuit or transistors) in the trigger circuit are easily identified by the tester. To do this, measure the voltages on their legs, referring to the diagram. Having found a discrepancy, the element is changed.

But the transformer is difficult to check. Check all voltages (according to the diagram) on the elements of this converter. If everything is normal, the transformer is to blame.

It can be rewound, but this is a hassle, and the quality of such winding will again lead to failure. It is better to buy a new one (get a worker in TV shops) and install it.

In the LED backlight transformer, the potential difference is only 50-100 V. If it is not on the connector, you need to check how many volts are coming to the transformer. For this, it is better to remove it. If everything is normal, the transformer is changed, if not, the other elements of the converter are checked with a tester.

Read also:

In this case, a breakdown in the sound path. Check the supply and output voltages on the legs of the audio amplifier microcircuit (with a tester according to the diagram). If they are normal, the strapping capacitors and the input capacitors are to blame.

If the power supply is too low or absent, there are two reasons:

It doesn't come with PSU... In this case, all the elements going from the power supply unit to the charger are called and the failed ones are changed.
Chip is unusable... It is easy to check by unsoldering the microcircuit. If after that the voltage appears and is normal, it must be changed.

This happens for many reasons. Here are some of them:

The signal from the receiving unit (tuner and its circuits) does not go to the input of the video amplifier... To check, you need to connect some kind of video signal source (computer, VCR, set-top box) to the “Video” jacks on the TV case. For example HDMI, VGA, tulips (yellow) and others.

If the image appears, the tuner, microcontroller and their circuits are to blame. The microcontroller can be checked quickly. He is responsible for the operation of buttons, input, audio and video signals. If, when you press the buttons, you can enter the menu, and it is displayed on the screen, then the microcontroller is not to blame. Check the potentials on its legs with a tester. If they all match the diagram, change the tuner.

The video processor is to blame... If nothing happened after connecting to the tuners, then check the microcircuit (video processor). Check all supply and output circuits for correct potential. If there is a discrepancy, the processor is 70% defective.

When checking the power supply unit, disconnect the secondary circuits, and instead, turn on ordinary bulbs to the appropriate voltage.
If you suspect that the "electrolyte" has lost its capacity, warm it up with a soldering iron. The electrolyte inside will boil and the capacity will recover for a short time. The method helps with frame scan malfunctions, when you can visually see how the screen opens as a result of heating.
If the high-voltage part is faulty, a faint hiss and crackling sound is heard. Turn off the light. In the dark, you can tell where the sparks are coming from.