LED lamps in TV repair. LED TV backlight repair at home

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Even the best quality equipment experiences various glitches and malfunctions. Therefore, every user should be prepared for the fact that they will have to repair the equipment with their own hands, because paying for the services of service centers can go broke.

Today we will talk about the most popular failure - a malfunction of the LED backlight on LG TVs. It is with this problem that ordinary users most often turn to service centers. Few people know that you can normalize the operation of the device on your own. No special skills are required, the main thing is to follow the instructions.

Before you start repairing the LG TV backlight, you should first understand how this component works, what are its functions and why is it even needed?

What is LED backlighting?

The abbreviation LED stands for Light Emitting Diode, which is translated from English as a diode that emits light. Speaking specifically in the context of the television equipment manufacturing industry, this abbreviation denotes the type of liquid crystal matrix and backlighting with light-emitting diodes.

After a new type of backlight for LCD monitors was introduced, manufacturers began to replace the abbreviation LCD in model names with the designation LED. Of course, LG TVs are no exception to this rule.

In fact, the motive for such changes was more likely to be marketing objectives than real necessity. The fact is that LED backlighting of matrices is not a fundamentally new technology for manufacturing screens for television equipment. It's just an updated way of lighting. However, the trend has harmoniously taken root, so the term Light Emitting Diode is still actively used today.

The most common TV matrices are based on the use of a cold cathode lamp, essentially the same as fluorescent lamps. As for LCD and LED models, they are characterized by light-emitting diodes.

It's no secret that LCD screens consist of liquid crystal pixels. The position of the crystal in a pixel determines whether the cell allows light to pass through. This is actually how the screen glows.

The quality of the screen matrix is determined by a huge number of parameters, in particular: the level of dark shades, viewing angle, static contrast, image refresh rate and even response time. Liquid crystal matrices are produced using several technologies. Let's list the most popular: TN, IPS, PLS.

As for the backlight itself, it affects brightness, color reproduction, coverage, and dynamic contrast. However, it is still worth evaluating the parameters as a whole, taking into account the type of matrix and backlight.

Thus, when buying a TV with LED backlighting, the user receives:

balanced contrast;
rich brightness;
high picture clarity;
color palette.

In addition, LEDs consume much less electricity, about 40%, than their counterparts. Fluorescent lamps, which are also used in the production of television equipment, contain mercury, which has a negative impact on the environment. In this regard, the advantages of LED are obvious.

There is no point in arguing; modern TV devices with backlighting consisting of LEDs ensure the transmission of the brightest image possible. Dynamic contrast appears - adjusting the brightness of the diodes for different areas of the monitor. The image becomes more realistic.

Regulating the glow of the diodes directly while watching TV also has a positive effect on the black level. When dark shades appear, the backlight level decreases, resulting in the screen becoming darker.

Reasons for backlight failure

High-quality television equipment can work for quite a long time, so problems with backlighting appear after an impressive period of time. Unfortunately, the same cannot be said about Chinese manufacturers.

Why is there no backlight? There are several reasons for the malfunction, let's analyze each of them:

A certain line of diodes has burned out. LEDs are characterized by a serial connection type, which means that if one element stops working, the entire component fails. However, voltage (approximately 200 volts) continues to flow to the light bulbs.

Problems with LED driver. The image disappears on the LG TV due to the fact that voltage, on the contrary, is not supplied to the LEDs, so they do not light up.

Manufacturing defects. Sometimes only one LED does not work, but the screen of the TV device does not light up.

The user sets the maximum brightness of the image, which leads to an increase in voltage, as a result of which the diodes cannot withstand and burn out.

Sometimes incorrect settings of the voltage supplied to the LEDs are the fault of the store where you purchased the TV. They try to attract customers with a bright picture.

Now you know why the LED backlight of your TV fails. This breakdown occurs quite often, but if you follow the manufacturer’s recommendations, you can significantly extend the service life of the device.

Professional repairmen using special equipment will determine which module has failed. How can an ordinary user understand that the backlight of the LG TV screen is not working? Now let's look at the basics of diagnostics.

TV diagnostics

How to determine that it is the backlight that has failed? It all depends on the symptoms. For example, an LCD TV starts from the remote control, but there is no image on the screen. Point a flashlight at the screen and you will see a dim picture. Essentially, the flashlight functions as forced illumination.

Based on this, we come to the conclusion that either the LED driver or the backlight is broken. To specify the source of the problem, you should disassemble the TV and carefully inspect the hardware components.

Remember that you should only disassemble the TV case if you have previously had similar experience. If you don’t have the skills, then it’s better to contact a service center. Once again it’s better not to take risks. Since there is always the possibility of making things worse, that is, aggravating the initial breakdown.

To dismantle the back panel of an LG TV device, simply unscrew the special bolts that provide fixation. This is not difficult to do. First, disconnect the supply and remove the fasteners. If the cover still does not come off, then you need to find the blocking bolt.

With the back panel removed, you should check the backlight and output voltage. For example, if the backlight voltage is 100 volts, then the component has failed.

In most cases, LG TVs are equipped with an LED lens array, which is located around the entire perimeter of the screen, providing clear lighting. To get to this part and repair it, you must first dismantle the matrix.

Now you know what to do if the TV turns on, but there is no picture.

Disassembling the product

Regardless of the model, television equipment is equipped with three key boards: main, T-con and power adapter. You will see them immediately after removing the cover.

Disassembling an LG LCD TV is an extremely complex and time-consuming process; use extreme caution as there is a risk of damaging other hardware elements. To carefully disassemble the TV, follow these recommendations:

prepare in advance the work area and two tables close to each other, on which the components will be placed: matrix, LED strip, bar;
Before starting disassembly, wash your hands to avoid contaminating the filters or matrix. In the future, this will negatively affect the image quality;
special attention should be paid to decryptors; if you are not careful, you will simply break the cable.

Step-by-step instructions for disassembling television equipment:

Disconnect the cables and unscrew the bolts located between them to disconnect and remove the T-con board.

Remove the metal protective elements from the decoders. To do this, unscrew the fastenings located on the sides and the bolts. As a result, decoders will be supported exclusively by rubber mounts.

It's time to remove the front frame of the device. Unscrew the screws around the entire perimeter and place the product on the back panel. Remove the frame.

Turn the screen over while holding the matrix. The decoders should be on top, you can disconnect the rubber fasteners holding them, the main thing is to do everything very carefully.

We disconnect the matrix and place it on a previously prepared table so that it does not interfere with the backlight repair.

In principle, anyone can disassemble a TV device, the main thing is to be as careful as possible.

Determination of non-working LEDs

Previously, we looked at the process of disassembling the TV, now let's proceed directly to the repair. To replace the LEDs in the backlight, carefully unclip all fasteners and then remove the plastic frame. We remove the scattering films to open access to faulty elements.

The structure of the LED backlight directly depends on which particular model of television equipment we are talking about. For example, for LG 32LB582V there are three rows of LEDs for 6 pieces. Model 32LN541U has one more diode in each row.

Television equipment that uses this lighting technology is characterized by a series connection of diodes, so if only one element burns out, then absolutely the entire system will fail.

If the driver breaks down, the entire system will lose power. If only one diode burns out, then there will be voltage, but there is no proper lighting. The circuit is open. Therefore, you need to change the faulty LEDs of your LG TV for correct viewing.

Approximately, the backlight system has about 18 diodes; voltage measurements showed that 140 V is supplied without loading, which means that each element separately accounts for approximately 7.8 V.

Why are all these calculations needed? The voltage level of each strip and the total load allow you to calculate the power of the LEDs used. Finding a faulty system element is extremely difficult. If the fasteners are not burnt, then you will have to recheck absolutely all the diodes one by one.

Replacing LEDs

Replacing the backlight of an LG TV yourself is extremely difficult, and it is possible that you will encounter certain difficulties. Let's assume that during the diagnostic process you were able to identify a couple of damaged diodes. Purchasing a strip of new light bulbs is very problematic. Service centers do not supply these parts, so the only option is to purchase from the manufacturer. It is clear that you will have to wait a very long time for delivery, not to mention the cost.

To avoid buying a strip, you should replace the LEDs in LG LED TVs one by one. You can buy it on the market. Mostly they sell already soldered parts, but that’s okay, the main thing is that they work.

Remember that absolutely all planks are fixed with double-sided tape. Therefore, they need to be heated with a soldering hair dryer to loosen the fixation of the adhesive tape. Fix the LED strip in a special holder. Warm it up with a hairdryer from below, eventually the tin will melt. This is how the broken part is removed. Soldering is carried out in a similar way; this is the only way to change a part without damaging it.

Remember that in the factory, absolutely all lenses are attached with a compound, therefore, be extremely careful when dismantling them. Each of them will have to be installed in its place. So as not to disturb focus.

There is one more subtlety: it is possible that you will come across LEDs with a large negative platform, therefore, the positive one will be smaller. Trim the contact point to solder the diode.

If the paint is slightly damaged, that's okay. The remaining structural elements are soldered using a similar principle. As for the lenses, they need to be glued using superglue.

Note.

Hi all!

I have a lot of information on the website on repairing and replacing LED backlights, and on repairs lcd backlight And replacement CCFL lamps no information.

Well, this article will, in some way, correct this shortcoming.

Everything you need to know about backlighting before you climb inside your monitor or TV.

1.The first and main signs of problems with the lamp:

— the image has acquired a constant or periodic pink tint;

— the backlight goes out completely after switching on or after a while, while the sound remains and the picture can be viewed if you bring the lighting device to the monitor. A similar symptom may indicate problems with the inverter, which is responsible for transmitting the signal to the lamps.

Quantity lamps in LCD on monitors there are usually at least 4, and on TVs it can be one or several. This depends on many factors: the age of the device, its diagonal, etc.
Before replacing, you need to make sure that the new light elements fit the parameters. For this purpose, there are tables on the correspondence of lamps to display diagonals. Better to follow it. It is possible that you will be able to install a lamp with a length difference of 1-2 mm, but this will take more time and effort.
The process of replacing lamps for a beginner will take approximately 3-4 hours if you follow the instructions and do not experiment.
Caution doesn't hurt! When working with an inverter, be extremely careful, because its voltage output is approximately 1000V. And when you change the lamps, try not to break them, because... they are very fragile and contain mercury vapor.

Process replacing lamps lcd backlight **TVs and monitors.**

For the lamp replacement procedure itself, you will need:

- a well-cleaned room and a clean surface;

— rubber gloves (medical gloves are ideal);

- a sharp thin knife (for example, a stationery knife);

— heat-shrinkable tubes;

- Screwdriver Set.

So, you need to get to the lamps. At first monitor (TV) must be freed from the protective plastic box - unfasten it from the narrow panel, which is located along the perimeter of the screen in front. Then carefully, by unscrewing a few screws, remove the entire LCD module from the metal frame.

Now begins the most difficult work that requires patience and accuracy - disassembling the electronic panel and module into components. To remove the matrix (and it will have to be removed), you will need to arm yourself with tweezers and peel off the protective film from the electronic board (matrix decoder). This must be done carefully, because the thickness of the decoder is only 1 mm, and it is connected to the matrix by the thinnest data lines. If you try to cut off the film or pull harder, a breakdown will inevitably occur, after which it will be impossible to restore the functionality of the element.

When removing the matrix, like other elements, you need to wear gloves, because finger stains will subsequently be reflected on the image. In the same way, dust and other debris will make themselves known, so you should minimize their contact with open elements.

After removing the matrix, a set of filters and a light guide, where the lamps are located, will come into view. They can be located in pairs in pencil cases at the top and bottom of the monitor or in horizontal rows along the entire perimeter of the screen. In rare cases, it may not be necessary to completely disassemble the LCD module, because sometimes cases with lamps are removed in more accessible ways. But all this can be learned only in the process of work.

When you get to the lamps, you can immediately notice the faulty ones - blackened cathodes will tell about this. But if the lamps visually look the same, then you will have to figure out which one to change. The method of replacing a working (preferably new) lamp will be the simplest. If this method cannot be implemented, then using a special device you can create a resistance of approximately 1 kOhm-2 W through an inverter.

After replacing the lamps, perform the reverse process - collecting all the parts of the device into the original design. Assemble carefully to avoid fingerprints, dirt, dust and foreign objects. If everything is done correctly, the TV or monitor will work normally.

Replacing the standard CCFL lamp with an LED one.

Devices with an LCD system use CCFL lamps or, in our opinion, fluorescent lamps, which glow not by heating the cathodes, but by applying voltage to them. That's why they are called cold cathode lamps. Such a light source should ideally be replaced with an identical one. But we will briefly look at replacing it with an alternative LED lighting system:

First, you will need to disassemble the device according to the scheme described above.
Remove the lamps and remove the inverter.
Buy an LED strip of the right size and better white glow. You can find ready-made designs with a set of LEDs and a control device for them.
The LED strip is glued with double-sided tape to the place where the fluorescent lamp was.
Wires are connected to this design, which are brought out onto the board and soldered to where the 12V power supply is indicated.
The functionality of this circuit is checked and the monitor or TV is assembled.

This method has disadvantages and advantages. CCFL lamps definitely illuminate brighter and more evenly (better for the eyes), but LED strip is more affordable and less expensive. This backlight is not adjustable. Although you can try to create a more complex control circuit yourself, which will take more than one hour (maybe a day) or you can spend money and buy a ready-made design with a controller. But, perhaps, the main advantage of LED backlighting is significant energy savings and durability (120 years!!).

The ability to do something with your own hands, as well as repair electrical appliances, remains relevant today. It is much cheaper to replace a damaged part yourself than to pay a professional repairman. Moreover, repairs are often not as complicated as they seem at first glance. Today’s article will consider such a situation as replacing old lamps in a monitor with a more modern lighting product - an LED strip.

LED backlit monitor

In order for such a replacement to be successful, you need to know the sequence of actions, as well as some of the nuances that will be discussed in this article.

Reasons for replacing the light source

Today, liquid crystal monitors with screen backlighting are actively used. They replaced older monitor models that were less well made. Despite the fairly high level of technology, such products in some cases are equipped with lighting, organized using old-style lamps. And, as you know, old light sources did not have a long service life. For this reason, very often it is the backlight that fails in such electrical appliances. This breakdown is not so difficult for the monitor to seek help from specialists. If you wish, you can do all the repairs yourself.

LCD monitor

It is worth noting that despite the presence of a large number of monitor manufacturers, such devices operate on the same principle. This is very convenient, since knowing the operating principle of one monitor, you can relatively easily repair another model from a different manufacturer. Therefore, if you did not find the necessary part during disassembly in the usual place, you should not worry, it is probably hidden nearby and with proper examination you will definitely find it.

Why change to LED?

Today, the most modern and advanced light sources are LED products. Moreover, LED strips have become the most widespread.

LED Strip Light

In a situation where it is necessary to replace old used lamps in a monitor, the choice falls on this type of product for the following reasons:

long service life of LEDs. When properly connected, they can work without any visible decrease in brightness for almost 10 years! No other light source can currently boast such a service life;
such tapes have a self-adhesive base and can be easily attached to any surface, even the back of the monitor;
LEDs produce a bright luminous flux that is well perceived by the human visual analyzer. When working for a long time at an LED-backlit monitor, your eyes practically do not get tired;
The backlight glow can be absolutely anything;

Note! Despite the availability of a large selection of tapes according to the type of glow, it is recommended to choose calmer and more neutral colors (for example, white or yellow) for backlighting the monitor.

LED strip glow

LED strips are sold in reels of 5 meters. This length is quite enough to create an effective and high-quality monitor backlight;
relative ease of connecting the product to the circuit board of an electrical device;
low power consumption with a high-quality light source. Typically, LED strips operate at a voltage of 12 or 24 V;
absence of strong heating of the diodes during operation. This is a very important point, since it is due to severe overheating that the lamps originally built into the monitor design fail. It is worth noting that old-style lamps still often fail due to frequent switching on/off of the electrical appliance. But for LEDs this is not such an important parameter;
The tape is resistant to mechanical and vibration influences, which minimizes the risk of damage to the backlight during operation of the device.

As you can see, replacing the old lamps in the monitor with a more modern LED strip will give a large number of positive aspects when using the repaired monitor in the future.

Assessing the complexity of the breakdown

Before you begin installing the LED strip into the monitor, you need to disassemble it and evaluate the degree of its performance. There are situations when not only the backlight lamp burns out in the device, but also the failure of other important components of the electrical circuit. To identify all existing problems and generally assess the possibility of self-repair, you first need to unwind the monitor and find out the causes of the breakdown.

Monitor matrix backlight

The monitor matrix backlight lamps fail for the following reasons:

the presence of an initial manufacturing defect;
physical damage to the lamps occurred due to the device falling or hitting any object;
a short circuit has occurred on the metal parts of the lamp and matrix frame;
The backlight lamps simply reached the end of their service life and burned out.

If you spin the monitor, you can visually determine the presence of a malfunction of such lamps, as well as determine the reason that led to this type of failure.
But in order to replace lamps efficiently, you need to know the operating principle of the liquid crystal matrix, which is built into any type of modern monitor.

Operating principle of the LCD matrix

In modern monitors, all LCD matrices operate on the transmission principle. This means that the device must have a light source that will illuminate the matrix through.

Note! The quality of a monitor directly depends on the type of light source.

Types of matrix backlights

For televisions and stationary LCD displays today, the direct type of backlight is very often used. This means that the light source (LEDs and lamps) will be located over the entire panel area. At the same time, to illuminate the LCD matrix in modern devices, two blocks are used, each of which consists of two lamps. They are located below and above the monitor. As a result, they are placed in such a way as to create uniform illumination of the LCD matrix. This design allows the backlight to work even in a situation where one of the lamps has failed. This is where the fun begins, since the inverter is responsible for powering the lamps.

Inverter for powering lamps

When one lamp stops working, the inverter “sees” that the backlight has lost its uniformity. As a result, the inverter will stop operating to prevent further problems with the backlight. Thus, it is the inverter that is the reason why, after one of the 4 lamps goes out of operation, the backlight continues to function for some time.
Now that we have found out everything you need to know about the monitor backlight, you can start disassembling it and replacing the old-style lamps with LED strip.

Disassembly: step by step instructions

Disassembling the monitor proceeds as follows:

disconnect all cables from the inverter unit and from the monitor controller;

Disconnecting cables

use a screwdriver to unscrew the device;
remove the back panel along with the controller and power supply;

Note! In some places, you will need to do a little digging to remove the back panel.

Monitor without back panel

We continue to spin the device further. Thus, we get to the matrix (in the figure it is marked with the number 5), the decoder (6) and the light guide with light filters (7);

Monitor Matrix

After this, you need to remove the plastic frame around the perimeter. Underneath there will be two thin films that lie on top of each other. Under them we will find a light guide. The photo shows a light filter (8), a polarizing film (9) and a light guide (10);

Matrix components

under the light guide and faulty lamps will be detected;
Before unscrewing them, you need to pull out the reflective backing. Although this step is not needed for every monitor.

When you finally get to the lamps, you can determine the cause of the backlight malfunction. If the light sources are burned out, then there will be blackening at their ends. Also, the lamp itself could be damaged due to mechanical stress.

LED installation: step by step instructions

When you get to the non-working backlight, your further steps to replace it with an LED strip will look like this:

we take out old lamps from their “grooves”;
before work, it is imperative to check the severity of the inverter’s power supply so as not to receive an electric shock;
To do this, we find a 12 volt circuit. A couple of electrolytic capacitors are usually placed along the circuit. Next, we trace the path going in the direction of the inverter microcircuit and cut it;

Note! De-energizing the inverter must be done.

Carefully glue the LED strip into these grooves

Gluing LED strip

As a backlight, it is best to take an LED strip that has a neutral-white type of glow. In terms of width, it is recommended to use a model with minimal parameters. In addition, you need to select a strip according to such a parameter as the number of LEDs per meter of product. There must be at least 120 of them;
When the tape has been glued, we remove the wires from it and check the entire device for functionality. The new LED backlight can be powered from a 12 V circuit. In search of such an output, you need to carefully read the pins on the board. They must be signed. Also on the board you can find jumpers that provide 12 volt power. In them, to power the tape, you just need to solder the wires from the new backlight;

Connecting the tape to power in the monitor

but here a problem arises in which the backlight will always be on. At the same time, there is no possibility of adjusting the brightness of its glow;
To change this situation, you need to find a backlight brightness control circuit. The “ON” pin will turn the backlight on/off. If the matrix lighting is on, approximately 3 volts will be present at this output. Brightness adjusts the "DIM" pin. You can adjust the brightness here by changing the duty cycle of the PWM signal. To adjust the brightness, you need to connect the LED strip using an N-channel “field”. A signal from the “DIM” pin is supplied to the gate through a small resistor (100…200 ohms) of this part.

Note! “Polevik” can be taken from an old motherboard.

"Field workers" on the motherboard

At this point, the installation of the LED strip in the monitor to replace old and unusable lamps can be considered complete. But we need to put all the details together. Remember that after completing the replacement you should not have any extra parts left. If they remain, it means that you did not return something to its place.
When the monitor is assembled, you need to check the result of your work and evaluate the uniformity of the backlight of the monitor matrix.

If the backlight on the TV works partially, briefly or does not work at all, then straight hands, a set of screwdrivers, a soldering iron and several meters of LED strip will save the family pet.

Apparently several backlights are not working. Over time, they will all die out and the TV can only be used in radio mode. We will fix the broken lighting. More precisely, replace the old CCFL backlight with modern LED.

Why change CCFL to LED?

In my understanding, CCFL backlighting is a monstrous but fragile monster, which consists of inverters (which produce dangerous voltage), backlight lamps (thin and fragile), powerful metal screens for safety and a bunch of wires. And I have no idea what exactly broke there. Perhaps the lamps need to be replaced (150 rubles apiece, and there are 16 of them). Maybe the inverter is faulty (it’s difficult to find the same one in stock, and the price is more than 1000 rubles apiece). In general, a lottery.

And LED backlighting consists of an LED strip (1,000 rubles for five meters), connecting wires (we’ll find it in supplies) and any power source that produces harmless 12V (we’ll find it locally).

Advice for the budget conscious: if you are willing to wait a little, then buy the LED strip on Aliexpress. It's twice as profitable.

Preparing to replace the backlight

First of all, stock up on screwdrivers of all types and sizes. You will also need a soldering iron and soldering supplies. You will also need several hours of free time (it took me about 6 hours at a leisurely pace). And there is a lot, A LOT of free space to lay out all the insides of the TV without losing anything.

If you are ready, there is nowhere to retreat, read on!

LED strip for TV backlighting

I bought the most ordinary LED strip at a local store, without bothering with characteristics, color warmth and other things. I simply had no options. More precisely, there were two: either a strip of 60 LEDs (three diodes per 5cm segment), or a strip of 120 LEDs (three diodes per 25mm) - this is one meter. I chose the second: the gap between the diodes is smaller, and the tape can be cut in place more accurately.

I connected all five meters of tape to the power source. I found out that the current consumption does not exceed 1A.

Of course, the tape from the store will have all the certificates and parameters carefully indicated on the instructions. The tape will even have a tail for connecting to a power source, which will come in handy.

We disassemble the Philips Flat Tv 30pf9975 TV

The back cover is secured with 16 screws around the perimeter, 6 more are recessed in fairly deep wells, 2 more above the main block of connectors and 1 on the side block of connectors. Total of 25 star screws.

After removing the cover we will see this picture.

Two massive TV mounting beams are clearly visible here; they also need to be removed. Near the left beam, under a metal cover, a pair of backlight inverters is hidden. We remove the cover, it is on the usual “plus” screws.

We release the inverters from all connectors and carefully remove both boards. I believe that the inverters get quite hot during operation, which is why their boards are installed on a thermal pad. The gasket is not adhesive, but voluminous, so the board must be picked up and slowly peeled off from the thermal gasket. You can try to prick the gasket with a knife, it will be faster, but it will turn out like this.

It is most convenient to attach the inverter board from the contact side to the backlight lamps; there is no thermal pad there.

Now that the high-voltage dangerous inverters have been removed, we connect the TV to the network, pick up a multimeter and poke into all the contacts in search of the treasured 12V line. It is important that this line only works when the TV is turned on, and does not work in stand-by mode. First, let's check the power outputs of the inverters, of course.

Inverters operate on 24V, which is a bummer. But the audio amplifier board, among other things, receives 12V. We will feed from her.

We take 12V from the audio amplifier board. Ground on the black wire (rightmost), +12V on the leftmost pin or on the fourth, counting from ground. The fourth one is easier to solder. Therefore, let’s take the connector that was carefully included with our tape and solder it to the amplifier board. The wire can be clamped between the capacitors on the board.

Before we go into all sorts of troubles, let's connect the tape and check whether there is enough current from the amplifier to power the entire tape. And is the backlight working correctly?

Hooray! The strip lights up when the TV is on. And it does not light up when it is in stand-by mode. Now it's time to completely disassemble the TV and replace the CCFL backlight with an LED strip.

We film everything we can film. We remove the main board.

We remove the power supply and additional power supply board, remove the audio amplifier board.

An additional matrix cable will be found under the power supply. Let's take it off. The adhesive tape is only there because I already took the TV apart. We lift the dark brown holder upward and pull out the train.

After this, you can remove the metal casing, under which there is a backlight board. This board and the connecting cable to the inverters can be thrown away. The casing too.

We continue to disassemble and unscrew until we can pull out the central part with the screen from the TV.

Here we unscrew the 14 screws along the edges of the metal frame and remove it.

Now unscrew the screws from the plastic frame. Then we carefully release the cables of the matrix (after first removing the metal casing with the board from the back side, it can be seen in the photo in the upper left corner) and remove it.

Be careful with the matrix!

The matrix cannot be bent, so be extremely careful and place it on a flat surface.

Under the matrix there will be two thin matte films (do not confuse their order), a plexiglass backing and... Backlight!

On the sides, the backlight is in rubber bands, I bit out the wires of the lamps and pulled them out of the rubber bands (because otherwise I just have to unsolder them). It turned out like this.

Let's try on our tape at the installation site.

The result was 625mm tape, that is, five meters is enough for exactly 8 segments. Therefore, the segments will be located where the plastic CCFL lamp holders are currently located. Take the knife and remove the holders. We also bite out the plastic spikes.

Now let's move to the laboratory. We cut the tape into 8 pieces of 625 mm each, lay them in a snake pattern and solder them sequentially. Remember to observe polarity!

After soldering, we carefully check our snake, check the polarity, and only after that we glue the tape in place of the old backlight.

It turned out pretty crooked. However, if you choose between not working at all and working at least somehow, then “it will do.” Now let's put everything back together in reverse order. There will be unnecessary parts from the old backlight: inverters, cables, protective metal casings and mounting screws. And the inside of the TV will become more spacious, like this.

Please note: I did not shorten the wire going to the backlight. In the future, it will be possible to make a variable resistor on the case and control the brightness. And now the cable is laid in the old fastenings of the inverter cables.

In the near future, a smart-tv board or some kind of raspberry pi will be able to fit in place of the inverters; there is enough space here.

We finally assemble the TV, hang it on the wall, connect all the cables and watch. Unlike CCFL lamps, which shine in all directions, the LED strip produces fairly directional light, so it is quite noticeable against a plain background.

If I bought LED strip on Aliexpress, I could buy two five-meter skeins for the same 1000 rubles and make 16, not 8, segments. The result would be more uniform illumination. But, as I said before, it will do. Just compare it with what it was.

The LED backlight is almost invisible against a non-uniform background, which means watching TV shows is quite comfortable.

Now about the shortcomings. The brightness of the backlight is not adjustable. But eight segments give an average level of brightness. I plan to add another 5 meters of backlight to make it more uniform, but... To be honest, repeating the complete disassembly of the TV for many hours is very lazy. Perhaps someday...

And now to the benefits: the TV has lost 1100 grams. Here are all the extra parts on the scale.

I successfully sold all these parts at auction. And I earned 10 rubles. But I learned from the buyer that 90% of the problems were in the backlight lamps, that is, it was enough to replace them... If I had known where to get exactly these, I would have done so.

A little like and repost is better than a big thank you in the comments. For this reason, comments are turned off, and repost buttons are waiting for you. Please use it :)

LED backlighting is used in most modern TVs today. LG television devices are no exception. Although the company is famous for the high quality of its products, breakdowns still occur. And most often the backlight fails. It costs to repair the backlight in Russia from 1,000 to 12,000 rubles.

What is this?

Repairing the backlight on an LG TV means replacing failed elements with new ones. This type of work is very painstaking and is performed under certain conditions. Therefore, it is better to contact TV experts.

The following signs indicate that the backlight needs to be repaired:

When you turn on the device, there is no image (a black screen with barely noticeable silhouettes), but there is sound; you can switch channels and change the volume.
Dark spots appeared along the edges of the screen.
The image flickers.
When watching a movie, my eyes start to hurt a lot.

The backlight fails for the following reasons:

The inverter driver is broken.
The lamp in the matrix has burned out.
The backlight module is not functioning properly.

A competent specialist can determine what exactly is the cause of the breakdown.

Restoring the backlight on an LG TV goes like this:

The technician visits the home or the client brings the faulty device to the service center.
The TV is being diagnosed.
After identifying the cause of the breakdown, the technician negotiates with the client the cost of the work and the time frame for its completion.
The backlight is being restored (the TV is disassembled, the matrix is removed, non-functioning LEDs are replaced, equipment is assembled).
The television device is being checked.
The client pays the master and receives a guarantee certificate.

The work can last from 2 hours to several days. It all depends on the number of failed LEDs. In addition, spare parts for LG TVs are not always available.

What does the price depend on?

Repairing the backlight on an LG TV costs varying amounts of money. When setting prices, service companies take into account the following:

Diagonal of the television device.
Model of technology.
Availability of a warranty certificate.
Number of failed LEDs.
Difficulty of work.
Screen diagonal.
Cost of diagnostics.
Year of manufacture of the TV and its general condition.
Price of spare parts and components.
The need for a specialist to visit your home.
The qualification level of the telemaster, his experience.
Urgency of the order.
The prestige of the teleservice center and the pricing policy it uses.

The more LEDs that burn out, the more expensive it will be to repair your LG TV. The complexity of the work, the visit of a specialist to your home, and the urgency increase the cost. Prestigious service centers offer higher prices for their services than little-known companies.

Types of repairs

Depending on the number of failed LEDs, there are two types of repairs:

Replacing individual LEDs.
Replacement of the entire matrix.

Depending on the time that the customer allocates to the master for work, repairs can be:

Not urgent.
Urgent.

Depending on who repairs the TV:

Professional.
Independent.

Approximate price

Repairing the backlight on an LG TV costs approximately 1,000-12,000 rubles in Russia. Much depends on the screen diagonal. The cost of repair work depending on the diagonal:

up to 31 inches - from 1000 rubles.
from 32 to 36 inches - about 2500 rubles.
37-49 inches - 3800 rubles.
50-59 inches - from 5000 rubles.
60-74 inches - 6000 rubles.
over 75 inches - from 12,000 rubles.

Who to order the service from?

To repair the backlight of an LG TV, you need to have certain knowledge and experience. Therefore, it is not worth taking on such work on your own without certain skills. It is better to contact professionals at teleservice centers. Competent specialists work there, and the client is given a guarantee certificate for the service provided.

If the price of restoring the functionality of a television device seems too high, then you can look for a good repairman among private owners. But you must understand that such specialists do not provide a guarantee for their work. This can cause a number of problems when proving the fault of the master in poor-quality repairs.