Do-it-yourself sharp TV repair when the fuse is turned on

Actually the subject.
Rolsen C2116 TV.
Processor: TMP87CM38N
Video: TB1238AN
Power supply: I don’t know how to describe it, 2SC2688 generates 5V in the duty room, it looks like 2SA1015, 2SC3807, 2SD1710 generate everything else, trans - BCK-56A, feedback from 130V through the PC817B optocoupler, the circuit, as I understand it, is widespread, I already have it somewhere seen on the internet (without a separate duty room).
Chassis: sorry, I don't know what this term means.

Problem: I turn on the power - the fuse is flying. Transistors rang - alive, there is no short circuit in the primary unit.

I read on the forums - they advise the following: to unsolder all the secondary (these are three resistors, as I understand it), load 130V with a light bulb or a 500 Ohm resistor (about 40 W is obtained) and a 60 W light bulb in the break of the network wire, then turn on and crawl with an oscillator and a multimeter looking for problems.

Is this the right approach to getting started? Sorry for the lamerism, but for the first time in my life I climb into TV, before more and more on computers, receivers. Scary with high voltage, I decided to consult.

Photo of the TV power supply

Among all the malfunctions, the repair of power supplies takes the first place. In the article "TV Power Supply Malfunctions" I described typical power supply failures. In this article I want to describe the work and repair of power supplies in more detail.

You probably need to start with how to check the power supply after repair, so as not to cause it to break again. Although this method is considered controversial, I find it very effective.

So after repairing the power supply, you need to solder a 150 watt light bulb into the fuse break (it can be 100, but there may be a false glow), and solder the light bulb into the B + circuit break (line scan power 95-145 volts, you can simply cut the track) 40-60 watts. Please note that some power supplies will not start at light load.

This system works like this. When you turn on the network after repairing the power supply, if it is working properly, the first light bulb at the moment of charging the network capacitor (100-220μF 450V) lights up and goes out as it charges. A weak glow remains. A 60-watt light bulb glows according to the voltage in the floor.

With a faulty power supply, a 150 W lamp glows with full incandescence. In some cases, this saves the transistor, microcircuit from repeated failure of key elements.

In the second method, the power transistor of the power supply is not soldered and the level and shape of the signal coming to it is analyzed with the help of instruments (oscilloscope, multimeter).

In the description, I will rely on the diagram below.

Malfunctions can be caused by:

We check for a short circuit the elements of the mains filter, rectifier, thermistor - demagnetization system, the key and its strapping elements, as well as the key microcircuit (if the power supply is built on it).
When you find a faulty element, analyze the reasons for its failure. Failure of the transistor can be caused both by a voltage surge in the network, and by drying out of capacitors in the primary circuits.

The power supply does not turn on, the mains fuse is intact.
It should be checked for breakage: mains filter, rectifier, PWM - modulator.
Start by checking if the mains capacitor C has a constant voltage of about 300V (if not, look for a break in the mains filter, and also check the resistor R.
If there is + 300V on the capacitor C, check if it reaches the key transistor. You should also check the primary winding of the TP mains pulse transformer for breakage.
If all the elements are in good order, and the power supply does not turn on, it is necessary to check the arrival of pulses to the base (gate) of the transistor.
Also check the trigger R circuitry, usually high resistance resistors.

Check: the elements of the secondary rectifiers of the power supply, the loads of the power supply for a short circuit, the elements of the protection system (monitoring circuits for the output voltages), feedback circuits (modulator).
With the secondary circuits and their loads, I think everything is clear, it is necessary to check the rectifiers (diodes) and filter capacitors.
In the protection circuits, check the optocoupler and its piping.

With regards to the feedback circuits, check the zener diodes, diodes, capacitors (usually 4.7-10- 47 microfarads).

Network capacitor, capacitors of the PWM strapping, serviceability of the optocoupler and its strapping.

In this case, proceed as follows:

• check the soldering of the power supply elements for ring cracks;
• check the elements in the hottest places on the board by identifying them by blackening.
• In the event that a malfunction manifests itself when the TV is warming up, it is possible to localize the defective element either by cooling (cotton wool soaked in acetone, alcohol), or to speed up the occurrence of a malfunction by provoking it by heating one or another element with a soldering iron.

Hello! Please help me choose an analogue power supply unit (Wene-wn220a-3 24V 7A) for the Chinese TV no. Found a similar one to ebay, but I'm not sure about the insides. And what parameters should be used to select an analogue?

Two parameters are needed: 1) Voltage. Should be similar, in this case 24 V. 2) Amperes. In this case, 7 A. This parameter should be at least 7 amperes, but it should be borne in mind that the larger this number, the more expensive the power supply will be.

tel JVC-AVG14T. When turned on from standby mode, an image appears. and stars. and after 5 seconds everything goes out while the green LED blinks at a frequency of 1 time per second. and does not turn on anymore. It is necessary to turn off the PCN, then everything will be repeated. Changed all the electrolytes in the B / P, optocoupler, zener diode and transistors near it, help! THX.

It is necessary to check the diodes of the secondary circuits, horizontal scanning and vertical scanning.

help Blow fuses on TV Meredian Model TK-5411

The power supply does not start and the light diode does not tell where to look for the cause. Tv polar platform Т08-29к

Doesn't say anything, let's get a model.

Hello!
The power supply unit is assembled with a key on a composite field, a VESTEL VR2106TS TV, a chassis on an AK-36 tr-re, if I'm not mistaken. Symptoms of malfunction: short-term periodic start of the power supply unit (clatter), while, in time, a whistle is heard, the power-on indicator LED blinks red.
How would you start troubleshooting? With the search for a short circuit in the load of the tr-ra, or a malfunction in the piping of the shim controller?

I would start looking for a fault in the secondary power supply unit, line and personnel.

can parallel to the lamp be switched on on the tra-tor 2 winding, having previously turned off the scan with the output stage and tdks?

Quite right. The light bulb is soldered to the plus of the capacitor 100 microfarads * 160v and the case (minus) of the chassis, track on a line or cut off the power or evaporate the transistor

In the power supply, the lamp 60-75 -95-150w lights up and immediately goes out, which means that the power supply is normal! (40w) I connected a light bulb in series from the trance, then the second end to the choke, those to the capacitor - maybe it is necessary, most likely after it (filter) I think that after the air conditioner am I right or not? thanks for the answer!

Hello! Tell me, after repairing the power supply, I put a light bulb in the break of the mains fuse and it began to start a horizontal scan, but intermittently (extinguished) the lamp and naturally when the start goes out! lamp 60 W and 100 I am afraid to put was the incident burned already on another TV set a bunch of tr-ditch and micro-circuits! It makes no sense to put a lamp in a line of 60 W, because there is a launch - you can even hear it! thanks in advance!

In place of the fuse, a lamp of 150 - 200 W, in a line of 40 W. Most of the line transistors have Pout - 50 watts. Disconnect the line all the same and see if it turns off.If there is, then the problem is in the power supply, no, then in the line.

repair of the TV's power supply still takes second place after the line

A huge THANKS to the author for the material. 111

Guys, help me in short on the Odeon LTD-150D TV malfunctions in the power supply, it seems to me that the problem is in the transistor, tell me where to go with the question?

If there is no knowledge in electronics, then definitely go to the workshop.

Yes, at the expense of the capacitor, I agree, I was poked into my little finger by a good 400V.

I checked all the elements are in good order and the voltages are still underestimated what else to check

Does winding 2 work for itself?

Winding 2 monitors the mains voltage and generates a feedback signal proportional to the secondary voltages.

When repairing the power supply, be sure to discharge the line capacitor. Its charge may damage or shock something.

The dream of people to be a bird did not become a reality.
You are not a bird, man! Don't poop anywhere!
... (c) A. Laertsky.

The resistor is visible and stands as a protective one. In case of installation by "craftsmen" of non-standard fuses.

What kind of power supply, already a pulse one or with a conventional transformer?

Ideally, try to search for a scheme on the internet (for a long time and most likely not on Russian-language sites)

Scribe BP This was already clear after the first blown fuse.
And changing the current-limiting resistance was generally pointless, without repairing the power supply unit. With the same success, it was possible to put a nail.
You can't do it yourself, sorry.

Check:
rectifier bridge diodes
power transistor or microcircuit (I do not know what is there)
change electrolytes to NEW
ring all resistors, diodes, if any, except for the bridge

if there are zener diodes in the circuit, also check
when repairing, it is advisable to disconnect the power supply from the TV and load the line scan power circuit with a lamp up to one hundred watts. After checking and replacing defective parts, the first turn on is only through the lamp instead of the fuse

Last edited by Yarik on Jan 18, 2010 10:08 pm, edited 1 time in total.

Well, I haven't done it yet)) I must try

_________________
It seems that I understood what the reason for the misunderstanding is. Do you think what I think.

_________________
Look at yourself!

Did you change the microcircuit itself? If not, then you don't have to do anything else. It crashes in 99% of cases if the fuse is blown. In general, these micro-assemblies are dermal, unreliable.
Also keep in mind that if there is a short one in the load, then a new, repaired block will knock out immediately.
And the main mistake was - it was replacing a blown fuse. If the fuse burned out, and especially if it is all black or has a metallic tint on the glass inside, then it was an instant explosion of the wire, this is a very large current, a short circuit. And it makes no sense to change the fuse, this will only entail the subsequent release of other, still whole elements.

It is impossible to imagine a modern apartment or house without video and audio equipment. This equipment is used every day and therefore breaks down more often than others. There are several ways to repair TVs: send the technician to a service center, call a qualified technician at home, or make repairs with your own hands.

Before you start repairing a TV, you first need to make sure what the problem is. This will also help if you do the repair yourself, and then when the master comes, you will be able to explain the situation to him.

There are several types of malfunctions that can most often be found when a TV breaks down.

1. The technique does not turn off. In independence, a CRT TV or a modern LCD model has broken down, this malfunction is associated with a blown fuse. Only different models have distinctive details from each other. You should also pay attention to the diode bridge - perhaps it was he who burned out.
2. In both domestic and imported models, the potential can often go astray, for the function of which the posistor is responsible.
3. If the plasma TV monitor is broken, then the problem, most often, is interference or drops, light or dark stripes may appear, color changes while watching a program or movie.
4. The problem may be a broken cord or a faulty outlet.

If we take into account all the troubles listed above, it is worth saying that the most difficult breakdown is considered to be a screen malfunction. For example, light reflections appear on your monitor after the liquid hits the matrix or the TV is hit, then it is better to carry it to the teleservice. Here it will certainly be repaired, and if the warranty period has not expired, then it will be free of charge or at a reduced price.

See also - How to choose a TV for your home in 2018?

You can try to fix some malfunctions of TVs yourself. And it doesn't matter here - these are LCD models, LCD or LED, it is not necessary to call the wizard if you are confident in your abilities. But caution never hurts, because such TV models are not cheap, and without having any repair experience or knowledge in this area, you can only harm and aggravate the breakdown.

Before you start repairing LED or LCD TVs, you must carefully read the instructions, and also study the principle of operation of your model. Anyone, even one far from this field, will understand that the repair of TVs such as LCD or LED will differ from CRT models. In the latter case, you are guaranteed not to run into a faulty PTC thermistor. The main thing here is to determine the problem, why does the backlight not work?

If you are repairing LCD, LED models, then the only difference here will be what kind of backlight is used. If it is an LCD TV, then the backlighting is produced using fluorescent or fluorescent lamps. For TVs, LED backlighting is produced using LEDs. At this point, the differences between LCD models usually end.

The breakdown may consist only in the fact that there is no power, in order to check this on an LCD TV, you can do the following with your own hands:

• open the back cover of the model;
• remove the wires connected to the matrix;
• connect the working lamp to the contacts;
• there are also LCD models in which more than one light source is provided. In this case, all sources must be tested. Just dismantle the matrix and plug your TV into the network - you can see which LED is the problem.

When a broken lamp in an LED or LCD TV is identified, it must be replaced. This stage requires maximum care from the master, as well as the manifestation of special attention. In some cases, the lamp is removed without removing the matrix, you just need to move the protection elements with a rubber gasket and pull out the lamp with a soldering iron. Similarly, it is necessary to mount a working light bulb. Now we can congratulate you - you did the repair of the LCD TV with your own hands! Just pay attention to one important nuance - the new light bulb must fully meet the parameters and dimensions of the broken one!

To repair TVs yourself, look carefully at the matrix! If there are "unhealthy" streaks here, then the breakage is in the matrix. Have a new part? Then everything is simple! You change it and turn on the TV, if it works, then you have accurately identified the breakdown.

If the reason for the breakdown of LCD TVs is the screen, then it is best to purchase new models of LCD or LED equipment. It is not recommended to change the screen of LCD and LED models, as it is impractical! This also applies to the LCD matrix.

What could be the problem with a malfunctioning plasma TV? If it is necessary to repair plasma TVs, then proceed in the same way as described above. Just adapt it to your specific case.This description can be applied to any model of plasma TV, just stock up on the necessary tools in advance.

Although today most users prefer to use plasma, many still watch programs on more outdated CRT models. Let's find out how to repair a breakdown in such TVs. Below is a step-by-step instruction that will help you repair your electron beam product with your own hands.

• If you do not turn on such a device, check first of all the fuses. In these TVs, the back is made up of panels. Therefore, it is necessary to unscrew that part of the panels. Under such panels you will find a board and the power terminals must be connected to the fuse. They are connected to a conventional incandescent lamp, or rather to its base, after which the TV must be connected to the network. In the event that your equipment is in good working order, the lamp will go out after switching on, otherwise, when the fuse has blown, it will either not work at all, or it will constantly burn.
• The diode bridge may also break. It should only be borne in mind that it is necessary to regulate and repair it only after making a dial. In this case, not only a multimeter is used, but also a product passport, which indicates the main parameters of this model.
• The most difficult breakdown in a TV with a kinescope is a posistor. To check with your own hands, you must first turn off the power circuit, and then turn it on. In this case, the lamp must be monitored. If the work lamp goes out, then it can be said that the posistor is faulty. To make repairs, it is necessary to adjust the resistance of the network and only ventures to change this part.

But not only the matter may be in the posistor, transistors and capacitors burn out in CRT models. The diagnosis of this breakdown can also be made visually. If the condensate is blackened or cracked, then we replace it with a serviceable analogue. Now you know why the TV does not work and how to fix it yourself.

If the fuse has blown.

If your TV has a blown fuse, do not rush to change it, first find out the reason why it has blown.

The fuse in modern switching power supplies almost never blows out just like that, for no reason. Neither overvoltage, surge, nor undervoltage can cause the fuse in the switching power supply to blow.

Another thing is a linear power supply, where, apart from a transformer and rectifier diodes, there is practically nothing. However, linear power supplies are not used in modern TVs, at least we have not come across such TVs for repairs.

So, your TV has a blown fuse. First, let's try to figure out for what purpose a fuse is installed on the TV.

If you think that there is a fuse in the TV in order to protect it from damage, then you are mistaken. The fuse will not save your TV from breakdown under any circumstances, even with overvoltage, when 300 volts or more are supplied to the network, the fuse will only work after some part in the TV's power supply fails, for example, a power transistor or diode bridge ...

What is a fuse for, if it does not save from breakdown even with a power surge?

A fuse is not needed to save your TV from damage, but to protect it from fire.

Never change the fuse until you find out the reason for its failure and fix the failure that caused the fuse to work. Moreover, do not replace the fuse with a jumper.

You run the risk of burning down, in the truest sense of the word, your TV, and with it your apartment.

If this article did not make any impression on you and you nevertheless decided to change the blown fuse, pay attention to its amperage.

In my practice, there was a case when the owner of the LOEWE ACONDA TV installed a self-tapping screw, suitable in size, in place of a blown fuse. The entire power supply was blown apart, the power transistor was blown to pieces, it took half a day to restore the melted tracks on the printed circuit board.

Naturally, the cost of repairs doubled, and the self-tapping screw could not be removed from the fuse terminal, it was necessary to solder it together with the terminal.

Iron Reindeer Herder
Posts: 11266

Warnings: 1

Posts: 119

Warnings: 1

Posts: 119

Iron Reindeer Herder
Posts: 11266

Warnings: 1

Posts: 119

Probably, many are familiar with the situation when the TV stopped showing signs of life when the owner intended to turn it on. Now we are calm about this, since we understand that you can use another TV in the next room or in the kitchen, and the faulty device can be repaired over time. But, if you look back thirty, forty years ago, the refusal of the TV to turn on would be perceived as a big nuisance. TV then, despite the ideology of the programs, for many people was the only window into the world. It was in no way possible to skip the episode “Seventeen Moments of Spring”, and the feelings about this seemed quite reasonable.

There is no doubt that the technique has become more reliable and technologically advanced over time, its weight and dimensions have decreased, and many new user and multimedia functions have been added. However, nowadays, as well as at the dawn of its formation, television receivers are sometimes prone to failures when turned on. There may be many reasons for this, and the apparatus itself is not always the “culprit” of such strange behavior.

It is quite easy to verify the opposite. You need to check the electrical outlet where the cable from the TV is inserted. Plug in a table lamp and make sure it works. Remember where your device has the power button, and if there is one at all. This is no joke, many owners forget about its existence, using only the remote control.

The assortment of TV sets is so diverse and wide that even a master on TV in a model not very well known will take some time to find the mains switch. These elements of the scheme tend to hide in nooks and crannies, below, on the side, behind and be completely invisible. Accidentally hitting this button and not noticing it, then you can ask for a long time the question "Why does the TV not turn on?"

Of course, situations with a button or a bad outlet are not typical and are quite rare, but by checking these things it is worth starting to diagnose the reasons why the “box” does not want to turn on. Most often, the receiver itself is to blame and the owner has to make a decision whether to call a master or fix the TV with his own hands.

For many men who consider themselves technically literate, the issue of TV repair does not seem so difficult. “There you just need to replace the fuse, or something else, but to fix it you need a tester, a soldering iron and a circuit,” some confident people think so. However, the desire to repair the device on its own can decline after the cover is removed from the device and access to the boards and blocks of a modern TV is obtained.

The fuse, as we are used to seeing it, in the receiver, most often, is one and in most cases intact, if there were no farce-major circumstances in the form of a thunderstorm or large voltage surges in the electrical network.It may well be that the fuse on one of the boards has blown, but most of the "fuses" are now made in an SMD case and the search for a faulty one may take a long time, since there can be dozens of these components, and they are located in any television unit. It is rather difficult to visually determine their presence in the circuit and distinguish them from similar in appearance capacitors or resistors without proper skill.

Let's say the search was successful. Here it is - a burnt out "fuse" (fuse), which needs to be replaced and the hope that the TV will again delight us with juicy stories and heartfelt stereo sound will come true. However, joy can be premature. Questions should arise: "What is the rating of the defective fuse?" and "Why did it burn out?" If you don't think about these things and just solder a wire instead of a spare part, you can discover a lot of new things: see the smoke from a large microcircuit or hear the crackle of exploding transistors. This means that you have not found the cause of the blown fuse and, as a result, significantly increased the cost of further repairs.

For an experienced TV technician, the socket for the fuse in the power supply unit hastily wrapped in wire, causes sacred awe, horror in the eyes and the understanding that this device cannot be restored quickly and painlessly, that you cannot earn a lot, and you will have to “sit” with it for a long time, looking for changing what in ordinary life is not in the habit of failing. The most unpleasant thing in this case is the unpredictability and lack of logic when searching for defective parts.

Situation analysis and assessment of the factors affecting the occurrence of a malfunction are an integral part of the professional skills that an experienced TV master... Finding the root cause due to which various components of the television chassis, including fuses, can fail, is the main task of a specialist. You cannot repair, relying on "chance", without having firm confidence that the defect will not recur in the future.

A simple example. Panasonic CRT TV does not turn on. Measurements show that a 56 volt zener diode is broken in the tuner tuning voltage generation circuit, which performs a purely protective function, and its presence or absence in a properly operating chassis is not at all necessary. Due to inexperience, when repairing with your own hands, replacing this part leads to its repeated burnout. If the zener diode is not installed at all, the TV can turn on and work for a while until the line transistor, frame microcircuit or line transformer burns out. The reason for this behavior is in the overestimated voltage that the power supply gives out, and if even deeper, in the loss of the nominal capacity of two electrolytic capacitors of 47 microfarads. in the primary circuit of this block. This is the root cause of all troubles.

There is much more to be said about why the TV won't turn on. This note focuses on the human factor in such a situation and on the fact that always when repairing a TV, as, indeed, any technically complex device, one should look for the cause and eliminate the consequences caused by it. An attempt to restore the TV's performance on its own may not always end in success. You need to be ready for such a turn and think a hundred times before deciding on this step. It may be worth calling a foreman on TV for repair and, accepting a job, pay, first of all, his experience and knowledge, and not the ability to solder and use a tester and a circuit.

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According to the statistics of service centers, failure of power supplies is the most common cause of malfunctioning TVs. In modern TVs, switching power supplies of various designs and schematic constructions are used.However, most of their inherent malfunctions are similar, so the method of dealing with them can be used in various TV models.

Let's take a look at common device malfunctions associated with the operation of the power supply, their external manifestations, as well as ways to eliminate them.

This malfunction can be caused by the following reasons:

• Problems in the kinescope demagnetization system;
• Faults in the mains filter and rectifier;
• Failure of the transistor switch.

1. To find the cause of the problem, first of all we check for traces of a short circuit in the elements of the mains filter and rectifier of the power supply.
2. Then we check the health of the thermistor (posistor), which is responsible for the correct operation of the screen demagnetization system.
3. We make sure that the transistor switch and all the elements of its strapping are working correctly. If the power supply is built on a key microcircuit, then we check its serviceability.

At the same time, it is not enough just to find the failed element. It is important to find the cause of the malfunction. For example, a malfunction of the key transistor can be triggered by a sharp voltage drop in the power supply network or by the failure (drying out) of the electrolytic capacitors of the primary circuits.

In this case, suspicion may fall on a power filter, rectifier elements and a PWM (pulse-width) modulator, which should be checked for breakage.

1. Let's make sure that a constant voltage "hangs" on the network capacitor (about 300 V). If there is no voltage, then you should look for a break in the power filter or check the health of the resistor.
2. We check if the voltage reaches the transistor switch. We make sure that there is no breakage in the primary winding of the pulse mains transformer.
3. If no faults are found, we check whether pulses are supplied to the gate of the transistor, which works as a switch.
4. It does not hurt to check the health of the starting circuit resistor, which usually has a high resistance rating.

In this case, you should check the serviceability and absence of short circuits in the secondary rectifiers and power supply loads, as well as in the protection systems (output voltage level control circuits) and feedback (modulator).

In rectifiers, special attention should be paid to the serviceability of diodes and filter capacitors, and in the protection system, it is necessary to check the serviceability of the optocoupler and its accompanying elements (strapping).

In the feedback circuits, capacitors, zener diodes and diodes are subject to verification.

In this case, it is required to check the serviceability of the network capacitor, the elements for ensuring the operation of the PWM modulator and the protective optocoupler.

In case of periodic problems in the power supply

To find the causes of the malfunction, you should use the following algorithm:

• Carefully examine the soldering points of the power supply elements for the presence of circular cracks;
• Find elements with a blackened case in the power supply circuit, which indicates their overheating;
• If the malfunction begins to manifest itself only after the TV has warmed up, then the culprit can be calculated by artificial cooling (wetting with alcohol or acetone) or heating (with a soldering iron). The nature of the behavior of the power supply unit in this case can significantly narrow the circle of troubleshooting.

You can find the nearest service center, get advice on repair or order a master's visit through our rating of TV repair service centers.

Hello everyone. Today, a TV is being repaired, which broke down thanks to the electricians, who decided that the 220 volt voltage in the outlet was not enough, and threw another phase all over the street. As a result, a bunch of burned out TVs and other equipment, fortunately, in many cases, only the fuse burned out. By the way, users' complaints to the same RES did not give anything, they say, everything is fine with them, but from what it is not clear. Well, okay, let's start repairs.

So, the TV is being repaired WEST C2902FS with a breakdown "does not turn on". The owner of the TV decided to repair it himself, but replacing the fuse, the TV did not work.

Removing the TV cover, we immediately see a swollen network capacitor 330μF at 450V. The electrolyte from the capacitor flooded the floor of the board, so it had to be thoroughly washed out with alcohol, and then wiped dry.

View of the board after removing the cover

First of all, the diode bridge rang, but fortunately it turned out to be intact. To start working normally with the board, the mains capacitor was removed. After that, a picture with a burned-out PWM controller opens to the eyes. In the shimka, part of the case flew off from the voltage drop, only the name remained from the inscription STR G86 ...

I did not find a circuit for this particular TV, so after looking for a few circuits on the Internet, I came to the conclusion that my TV uses a controller of the type STR G8656, which perfectly changes to a similar microcircuit like STR G5653.

power supply state without controller PWM

Since I did not find the chassis circuit, I used a different circuit with an optocoupler. The elements on it are almost the same, but the reference designations are different.

Further, the capacitor, which was in the Drain circuit of the STR G8656 controller, was dropped out. He just blurted out, and in appearance he did not even approximately look like a capacitor. Its face value is 461 by 2Kv.

Degree of capacitor 461 for 2 kv

Along the way, ringing the elements, I found a faulty resistor in the circuit source 0.20 ohm and a punctured diode in the same circuit.

Power supply with new spare parts

Replacing all faulty elements, I began to prepare the TV for launch. Let me remind you that instead of STR G8656 I have installed STR G5653 no alterations.

faulty elements without STR G8653 (lost it somewhere)

To prevent the power supply from burning again, the first start was made through a lamp, which I connected instead of a fuse. It is imperative to turn off the demagnetization loop so that it does not give additional load to the lamp.

Here is the moment of truth! When turned on, the lamp came on for a second, which signaled the charge of the network capacitor, after which the standby LED came on. Measuring the voltage + B, it was 83.7 in, which corresponds to the norm. Installing the fuse, starting the TV. + B with left 134c, which is normal for these TVs.

Measurement of the standby voltage of the TV

Measurement of operating voltage

After 5 hours of running the TV, I successfully assembled it and gave it to the owner.

I will show the repair according to the scheme, in stages, at least as I understand it.

The scheme of "combustion" of the TV on the STR G8656 PWM

The overvoltage from the mains goes to the diode bridge, where it is successfully rectified and gets to the mains capacitor s810... Naturally, the voltage is higher than the maximum 450 volts, for which the capacitor is designed, and it swells. Further, the voltage through the transformer enters the capacitor s181 and the microcircuit itself STR G8656. She tries to swing the TPI winding, but since the current is too large, the transistor inside the microcircuit breaks through, after which our diode and resistance burn out. After the controller is closed by the PWM, the fuse is blown. Well, something like this. In general terms, I hope it is clear.

Thanks for watching. I hope it was interesting. Until new repairs.

Do-it-yourself TV repair is a responsible business, since today a large number of different models (LCD, LSD, CRT) are presented on the market, each of which has its own technological features. Therefore, the approach to each type of TV is individual; in some cases, special skills will be required (knowledge of electronics, experience with a soldering station).

Before proceeding with the repair of television equipment, it is necessary to find out the cause of the problem.

The most common problems are:

1. TV screen does not turn on - this can happen with an old picture tube screen and with the most modern television panel. Basically, this symptom is characteristic of a blown fuse.When repairing, it should be borne in mind that the appropriate fuse must be selected for each model. And also experts recommend paying attention to the diode bridge, power supply, wire, perhaps the cause of the malfunction lies in these elements. Read also what to do if Samsung TV does not turn on.

1. Faint, barely noticeable picture - such a breakdown happens with LCD / LCD monitors. The most likely cause of the malfunction: faulty diodes, device backlighting.
2. There is no sound, the screen "wheezes" - most likely, the sound amplifier or microcircuit is out of order. Also read what to do if there is sound, but there is no picture.
3. Monitor is on, no picture - Perhaps the cause of the problem is in the video processor or in the receiving unit.

You should be aware that if a darkening of the board or rupture of elements is detected during a visual inspection of television equipment, then it is not recommended to immediately start replacing parts. Since such factors indicate a short circuit that could have occurred in another section of the TV. Therefore, if you do not eliminate the cause of the short circuit, but simply change the failed elements, then the situation will repeat itself.

To repair television equipment, the following tools and equipment may be required:

• Screwdriver Set;
• hex keys (in rare cases);
• pliers;
• soldering station (for repairing modern monitors);
• screen layout (can be downloaded on the Internet);
• multimeter;
• oscilloscope.

Many LCD screen problems can be dealt with on your own. But you should know that these screens require more careful handling than, for example, CRT TVs.

First of all, the user needs to study the instructions for his model, and only after that start repairing the LCD or LED screen. You should be aware that LCD TVs use fluorescent bulbs for backlighting, while LEDs use LEDs.

The TV may not function due to lack of power, to check this, you need to do the following:

1. Open the back cover of the LCD TV with tools.
2. Disconnect the wires that are connected to the device matrix.
3. Connect a working light bulb to the contacts.
4. Some panels have more than one light source, in which case they must be tested as well. This can be done as follows: pull out the TV matrix and connect it to the network, it will immediately become clear which lamp is out of order.

After the faulty luminaire is found, it must be replaced. This procedure should be carried out as carefully as possible. In most cases, the lamp can be taken out even without removing the matrix - you need to move the protection elements and get the burned out part using a soldering station. Then a new lamp is installed in the same way.An important rule is that the new lamp must be completely identical to the old one.

Another common problem with these models is damage to the monitor. But in this case, it is not advisable to repair LCD TVs, since it is easier to buy a new screen. This test scheme can also be used to repair plasma televisions of all types. Read also how to fix the LED backlight yourself.

Each manufacturer has its own weak points, so below is a selection of the most common LCD screen breakdowns.

Often, users of this brand are faced with such a problem that when turned on, the device beeps without interruption. This symptom usually indicates that a leak has occurred. It is recommended to try replacing the preout stage diode.

Another common problem is that the monitor turns on and off itself. The main reason for this breakdown is a failed transistor, it is necessary to replace it.It is recommended that such malfunctions be eliminated on their own only by people who have experience in repairing television equipment.

DIY Philips TV repair is recommended if the problem is minor: settings are lost, cable replacement is required.

If the breakdown is complex, then it is better to entrust its elimination to specialists who will not only professionally perform repairs, but also issue a guarantee. Therefore, if the repaired screen stops working again, the user may demand a refund.

LG flat screen owners may have a problem saving settings. Such a problem does not require contacting the masters, you can repair the LG TV yourself. It is enough to switch the device to another operating mode, and all settings will be saved.

As well as in the case of other LCD models, if the problem is serious, then it is not recommended to repair an LG TV with your own hands, it is better to contact a specialist.

Despite the fact that today the majority of consumers prefer the most modern plasmas, CRT screens are still in demand. These TVs have their advantages: they are inexpensive, easy to operate, and the quality of the transmitted picture is still high.

The main problems with CRT devices:

• the CRT TV does not turn on - just like on devices of a different type, first of all, you need to check the integrity of the fuses;
• a diode bridge malfunction is a common problem with CRT receivers, you can fix the TV only after making a "ringing", you will need a multimeter from the equipment;
• breakage of the posistor is considered the most serious problem; in order to check, it is necessary to turn off the power circuit of the TV, then start it again. After, observe the lamp, if it goes out, it means that the posistor is out of order. First of all, you need to adjust the resistance of the network, and then replace the part;
• burnout of a transistor or capacitor - such a malfunction can be easily replaced by visual inspection (on black carbon parts), repair is carried out by replacing the part.

Below is a list of problems encountered by owners of CRT TVs.

1. The Rubin TV buzzes loudly when connected - most likely, the photodetector needs to be replaced.
2. The ruby ​​does not turn on, the indicator does not light up - voltage surges in the transistor.

1. The Horizon TV does not have a blue tint, as well as the white balance is disturbed - this is mainly due to a break in the resistor.
2. There is sound, no image - the cause of the problem lies in poor contact of the power connector of the screen board. It is recommended to use a soldering iron to solder the harness into the Horizon TV board.

1. The screen does not turn on - there is a problem with the power supply.
2. A horizontal strip appears on the monitor - repairing a Vityaz TV consists in fixing a problem in the frame scan microcircuit.

Since the malfunction of the power supply is one of the most common problems of all types of TVs, it is necessary to study it in more detail.

Since all models of LCD monitors do not have fundamentally different design differences, therefore, the diagram below can be applied to all TVs (Toshiba, Horizon, Samsung, Sony, Rubin).

Repair of monitors equipped with a picture tube, for example, such as (ruby, sharp 2002sc, sony trinitron, vvk), as well as repair of Samsung TV, Panasonic. always starts checking the power supply.

Testing is carried out using an incandescent lamp, but before performing the procedure, it is necessary to disconnect Sharp c2002sc, Samsung or another screen from the load (horizontal cascade). The horizontal scan voltage can vary from 110 to 150 V, it depends on the size of the picture tube. It is required to find a sweep filter capacitor in the TV circuit. Next, you will need to connect a light bulb, in order to remove the load, it is necessary to unsolder the choke and the fuse through which the JV element consumes power.This scheme is used for sharp screens since 2002sc.

After that, connect the power adapter to electricity and measure the voltage, if the values ​​exceed the norm, you will have to check the feedback circuit of the power supply. If the power supply unit is in good condition, then the light bulb is removed and all the elements are soldered into place. This is the basic information on how to repair a TV with your own hands.