Dead pixel on lg tv what to do. What to check first on TV

The image on a TV screen is formed by dots, which in technology are called pixels. These dots have their own color, which depends on the transmitted video. This way you can create any picture on the display.

So that each pixel can take on any color, it consists of three areas, the so-called “subpixels”. It is these subpixels that the TV electronics control to form a picture. In television, it is customary to form a color image from three colors: red, blue and green. Therefore, each pixel consists of three subpixels with their own color (red, green, blue). If you look at the screen from very close, you can see these three colored areas at each pixel.

What is a dead pixel - a pixel that glows in one color regardless of the picture on the screen. It is not controlled by the TV's processor.

Dead pixels appear on the display in the form of a dot of the same color, which does not change with the change of scene. The color depends on the position in which the liquid crystal is stopped in the cell: if open, then white; if closed, then black. If one of the subpixels fails, the cell will have a permanent color color, and not just black or white.

Dead pixel on the screen

LCD screens consist of several layers, each of which performs its own functions. On the problem of appearance dead pixels only two layers are related. This is a layer with the liquid crystals themselves and a layer with thin film transistors (TFT). These transistors control the crystals in the cells that make up the pixels. The failure of such a transistor leads to the appearance of a dead pixel, because it becomes impossible to control liquid crystals. If the fault is in the layer with liquid crystals, then the liquid crystal in the cell simply becomes motionless and then, even with a working transistor, a dead pixel will still appear on the TV screen.

How to check for dead pixels on a TV

Considering that defects mostly appear at the production stage, you can identify dead pixels on a TV screen even when purchasing it in a store. The best way to check your TV for dead pixels is if the screen is painted a uniform color. That is, if we are looking for black dots, then put a white field on the screen. If we are looking for white dots, then submit a black field accordingly. If we are looking for a colored dot, then apply a field of a different color to the screen and carefully look at the entire screen; a dot of a different color (dead pixel) will be visible to the naked eye.

To check your TV for dead pixels in a store or at home, you can download pictures from the Internet to check in the required resolution (Full HD or 4K). We record them on a flash drive and connect it to the television receiver. By turning on viewing images from the flash drive, you look through the test pictures one by one and visually look for dead pixels at close range.

It will be impossible to make a claim to the store after the purchase., if the number of dead pixels meets certain standards.

The most unpleasant defect is when one of the subpixels fails and the cell turns a different color. Such a cell attracts attention to itself much more than just a dark, idle pixel. In the factory, the required transistor is removed from such a matrix, and the cell turns into a black dot, which is less noticeable on a working screen.

At home, some users perform the so-called massage of a point with a dead pixel. Pressure is applied with a soft object in the hope that the stuck liquid crystal will begin to work normally again. But with such a procedure there is a risk of making several more neighboring pixels inoperative. Is there some more software methods combating dead pixels. But it is best to immediately, after checking for dead pixels on the TV and a positive result, contact a service center.

Having ordered a TV online and gone to the store to receive the goods, the consumer often forgets to check the TV for dead pixels, as a result of which he runs the risk of being disappointed in the item he just purchased when he gets home.

Since the absence of defects in the liquid crystal matrix is ​​guaranteed only by manufacturers of premium display models, the average user has to be careful and check the screen themselves before purchasing.

Pixels are the units of the LCD screen matrix, thanks to which any image is created. The main property of a pixel is its ability to change color: electricity, the amount of which is regulated by a transistor hidden in the TV, causes microelements of liquid crystals to change their location.

Thanks to the rearrangement of red, green and blue subpixels and the intensity of the backlight, one or another color is formed at a certain point on the monitor - if a TV device has 4K resolution and displays content at a speed of 30 FPS, more than 250 million such “castlings” can occur per second.

Dead pixels on a TV are the smallest elements of the display that do not change color under any conditions.

Although this defect practically invisible to the human eye during dynamic cinematic scenes, the user may experience discomfort when viewing static images: “broken” dots stand out clearly against the general background and make it difficult to concentrate on the TV picture displayed.

Allowable number of dead pixels

Each TV manufacturer declares the acceptable level of dead pixels in the matrix - products, during a pre-sale inspection of which a number of defects exceeding the established limit were identified, should be considered defective.

Top companies such as Samsung and LG allow no more than two completely dark pixels and no more than 5 incorrectly functioning subpixels per million pixels: for example, the already mentioned 4K resolution consists of 8 million matrix units (3840x2160) and therefore can include up to 16 defective pixels and up to 40 “stuck” subpixels.

Since pixels that work properly during factory tests can fail already during the operation of the TV, the manufacturer is obliged to guarantee the full functionality of the matrix for a period regulated by international or domestic requirements.

If there are “extra” dead pixels on the TV display, the user has the right to free repair or replacement of the device.

Interestingly, the generally accepted ISO 13406-2 standard limits a company's liability to one year, while LG's Zero Bright Dot program limits it to three.

Reasons for appearance

The reason for the appearance of broken dots on the matrix of a color TV may be:

• overheating or hypothermia of the device. As a result of exposure to high or low temperatures, subpixels harden and lose their ability to move inside the liquid crystals;
• ambient humidity. High humidity is dangerous for the LCD substrate: when moisture gets on the matrix, illuminated areas or white dots on the display are formed;
• voltage surges. Crash in electrical network can lead to failure of the transistor, as a result of which the energy supplied to the RGB matrix will force the subpixels to take a fixed position;
• violation of production technology. It is worth saying that in most cases, manufacturing defects are caused by only the three factors presented above - during the production of the matrix, repeated procedures of washing, drying and lithography are carried out, the slightest non-compliance technological processes which leads to defectiveness of the final product;
• using a monitor to display static content. When displaying the same picture for a long time, the display transistor may burn out and the crystals may “freeze.” Even TVs with support are not immune to this problem. HDR technologies(10-bit and Dolby Vision).

Also, the matrix may be damaged during careless transportation of the TV device to the point of sale: despite the strong fixation in the substrate, liquid crystals are very sensitive to sudden mechanical shocks.

How to check your TV for dead pixels

To see broken elements of the TV matrix, it is recommended to use a special gallery of monochromatic images - there are no programs compatible with Smart-TV for checking the display.

The screen testing algorithm is presented using the example of searching for white dots:

1. Upload a special collection of images to a flash drive.
2. Connecting a removable drive to the TV via a USB interface.
3. Opening a monochromatic picture on the TV (in this case, black).
4. Inspection of the display: white broken elements should be clearly visible against a dark background.

To search for black dead pixels, you will need to use a light image, and to identify RGB defects, you will need to use any background that contrasts with the bug you are looking for.

Unfortunately, the user must rely only on the acuity of his own vision, since it is impossible to automate the described process.

External inspection upon purchase

Some resellers provide paid service checking the liquid crystal display for dead pixels: the user selects a TV, and the sales assistant tests the display using images uploaded to the device.

It is worth saying that paying for such a service makes sense only if you need to check a 4K monitor, the defective pixels of which are almost invisible against the backdrop of millions of working units.

Warranty case

The service center does not have the right to refuse the consumer to exchange a defective TV for a new one only if the manufacturer violates ISO 13406-2 regulations.

The standard describes permissible quantity broken elements of the display matrix for a particular class of device:

You can find out the display class from the technical documentation supplied with the TV. Next we will tell you what to do if you receive a refusal from the service center.

Treatment for dead pixels on TV

Treatment of a color TV (for example, made by Samsung) from broken matrix elements at home is as follows:

• launch of a special video. You will need to download a video clip that “warms up” the matrix onto a flash drive and play this video on the TV for 40-50 minutes;
• “massage” of inoperative units. It is necessary to press on the dead pixels using a regular cotton swab - it is important to understand that if you put excessive pressure on the matrix, the final result may be the opposite of the desired one.

It is worth saying that dead pixels can be eliminated in this way on any digital technology.

Bottom line

Now you know what dead pixels are and how to check for their presence in the matrix of a new TV yourself.

It is important that the consumer has the right to free service only after the device is recognized as not conforming to the declared ISO 13406-2.

Although liquid crystal panels have long ceased to be a dream, even when using the most modern technologies, there are defects that can greatly spoil the mood of a perfect purchase. In order to be completely satisfied with the purchased product, you need to check the TV for dead pixels when purchasing.

Today, liquid crystal displays are not something unusual or extraordinary. On the contrary, in addition to televisions, they are present in many devices: computer monitors, phones, cameras, navigators and other similar equipment. The basis of LCD or LCD technology is liquid crystals. After light from lamps or LEDs passes through a layer of crystals, a corresponding picture appears on the screen.

The matrix of a color TV is a huge number of tiny indivisible rectangular or round cells called pixels. In turn, each such object consists of red, green and blue subpixels. It is these colors, or rather their combinations, that are considered the basis of color television. The simultaneous lighting of all pixels forms a complete image on the screen. Moreover, the more pixels, the clearer the picture. If you look closely at the display, you can easily see the three colored areas of these objects.

The concept of dead pixels, the reasons for their appearance

The number of pixels on the display is so huge that it is almost impossible to guarantee their 100% serviceability. Often on the screen you can see dots glowing in one color, completely motionless, which even with a change in the TV image do not change color or location. It is these objects that are commonly called dead pixels. They can be black, white and colored. There are two reasons for the occurrence of these defects: imperfect technology and ordinary manufacturing defects.

Dead pixels occur in two layers: liquid crystals and thin-film transistors.

After the transistor that controls the liquid crystals fails, black (“dead”) dots appear, indicating non-functioning cells. Subsequent management of these crystals is simply impossible. Such defects are most visible on a light background. Some experts consider it impossible to “treat” them, others argue that using a laser it is possible to partially return the pixel to its working condition.

The second reason is the subpixel frozen in one position. This problem appears in the liquid crystal layer. Such a “stuck” object appears on the display as a white (burning) or colored dot. To eliminate this defect, you can use special programs or carry out a series of physical manipulations. There are cases when dead pixels, after some time, disappear on their own.

Thus, when choosing an LCD TV, it is not enough to pay attention to its appearance, the presence of numerous functions, ports, connectors. It is also important to check the device for matrix defects. Let's try to figure out how to check a TV before buying and protect yourself from purchasing low-quality equipment.

Allowable number of dead pixels

You can often see a picture in stores when a buyer tries to return a newly purchased TV after discovering defects on the screen, in particular, dead pixels. For the sake of truth, we note that usually a dispute between a store and a buyer ends not in favor of the latter. To avoid getting into an unpleasant situation, we recommend choosing a TV very responsibly. In particular, it is worth knowing how to point of sale check the LCD TV when purchasing for dead pixels, get acquainted with certain standards, according to which displays are divided into four classes.

How to check a TV in a retail chain

The information in the table indicates that first class products are completely free of dead pixels. The cost of a product depends on its class.

The picture is formed on the screen by all pixels of the display. For example, Full HD resolution (1920 x 1080) involves more than two million pixels. Knowing the acceptable standards for dead pixels and methods of checking for such defects, it is not difficult to choose high-quality equipment.

Device testing can also be done using special programs by connecting the TV to a computer or laptop. Often the buyer does not have a computer at hand, so it is extremely difficult to carry out such manipulations in the store. Now many stores offer a paid service for checking screens for defects. What to do in this case, should you agree or should you still try to cope with this work on your own?

The simplest way is visual inspection screen at close range to the presence of a dot glowing in a different color. An ordinary magnifying glass will be a reliable assistant in this check. Detection of black dots is possible when a white field is applied to the screen. To find white spots, just make the screen dark. Finding defective color subpixels can be made easier by changing the screen color one by one.

It is important to remember that some defects do not appear immediately, but only after the matrix is ​​heated. Pictures in the form of colored stripes, grids, and checkerboard fills will also help you quickly find malfunctioning subpixels that stand out from the general background.

If you are planning to purchase new equipment, first of all, study the relevant information, in particular, how to check the TV when purchasing it in a store. To carry out testing, you need to select special images and videos. They contain special pictures of different colors that appear alternately on the screen. Then write this information onto a flash drive, and then go get the TV. Videos are usually accompanied by music, which allows you to simultaneously check the quality of the acoustics.

Many today prefer new generation devices with Ultra HD resolution (3840 x 2160). They are characterized by excellent color saturation, perfect transition from one shade to another, the ability to adapt any format to 4K, excellent sound, and many additional functions. To check a 4k TV when purchasing, you need to use pictures with the appropriate resolution.

Is it possible to “cure” dead pixels?

Often, defects on the display appear during operation. Black dots, as mentioned earlier, cannot be removed on your own. As for colored pixels, there are two ways to get rid of them: physical treatment and hardware massage.

The first method involves using a regular cotton swab to massage the damaged area where the “stuck” pixel is located. Such manipulations are carried out in a circular motion with the device turned off. This method cannot be called completely safe, because careless movement not only will not save you, on the contrary, it may add to trouble.

The second method is to use special programs that are easy to find on the Internet. BadCrystal – does not always cope with the task, however, it’s worth a try. Practice shows that it removes stuck spots within a few minutes or a couple of days. The JScreenFix program is no less popular today. She not only finds the defect, but also eliminates it. Operating time from 20 minutes to 10 hours.

Thus, armed with the necessary test kit, you can safely head to the store for a new TV. Rush when checking the device is unacceptable. The test should be completed slowly, examining each section of the screen step by step.

To completely protect yourself from various unpleasant surprises, we can recommend this procedure for checking the TV before purchasing. Here are tips that allow you to check your TV receiver in a store., and you can limit yourself to only those that are suitable for your situation. And you can bypass those moments that are difficult for you to implement. The main thing is that you see a working TV and can evaluate the quality of the picture with your own eyes.

External inspection upon purchase

At first check the packaging for various damages(dents, tears), if there were any blows to the packaging during transportation, then the TV also suffered. Then check the presence of all correctly filled out documents, such as a passport for the device, a warranty card. The coupon must be filled out correctly by the seller (warranty period, date of sale, stamp), the serial number in the coupon must match the number on the TV.

Check the external condition of the TV and remote control remote control . Look for scuffs, chips, cracks, etc. The screws on the back of the TV should not show signs of tampering, otherwise your TV has already been sold and repaired.

By model name, serial number and the product code you can find out where and when this TV was made and for which country.

Even more detailed information The operating time and the number of starts can be found out from the service menu. But it’s better not to enter this menu yourself if you don’t know what it is. It is intended for specialists and the store is not obligated to include it for you. Incorrect operation of the service menu can lead to complete inoperability of the TV. To enter this menu, you need to enter a certain set of characters, which depends on the brand and model of the device.

After this, you can turn on the TV and check its operation, correct operation of the remote control, work with external sources ( USB flash drives, players, etc.). You can take your own flash drive and pre-record videos with it. high resolution, and pictures to check for dead pixels.

Checking for dead pixels

When forming a picture on a TV screen, all pixels of the display must be used. With Full HD screen resolution, the entire display field consists of 1920x1080 pixels, which is just over 2 million pixels.

And each point is formed from three sub-pixels (red, green, blue). Some companies may add a fourth sub-pixel for better color reproduction. If one of these sub-pixels stops working correctly, then the dot on the screen will glow the wrong color.

According to the rules, a certain number of non-working pixels is allowed; different standards allow a different number of defective pixels. So, having identified this defect at home in the form of one or two non-functioning pixels, you will not be able to return the TV back, so it is better to do this check before purchasing.

To search for defective pixels, you need to submit an image to the screen with a certain picture and examine the screen at close range. You can also use a magnifying glass. You need to look for a pixel that glows in a different color than all the others. The image resolution must exactly match the screen resolution.

Completely idle pixels, those that do not respond to the signal and are in a constant position, can be found in a uniform picture (filled with one color). Alternately, white, black and primary colors (red, blue, green) pictures are presented on the screen and look for pixels of a different color on them.

Broken pixel on a black background Broken sub-pixel on the screen

There are defective pixels that begin to work poorly when the matrix heats up. You will be able to identify them after the TV has been running for a while.

There are pixels that do not work correctly depending on the operation of neighboring sub-pixels. You can detect such defects if you present a picture on the screen in the form of a checkerboard fill, color stripes, gradations, or a grid. Poorly functioning pixels will stand out from general structure Pictures.

You can download the necessary pictures to check the image on your TV. The resolution of the test images is 1920x1080 pixels.

To test Ultra HD 4K TVs, test images.

You can read how to use the image data.

Non-uniform screen illumination

When a video signal with a uniform color fill (painted in one color) is supplied to the TV input, this color should appear on the screen without any color shades. But, due to technological features When manufacturing displays with LED backlighting, such uniform illumination is difficult to achieve. That's why It is advisable to check the uniformity of the color field even before purchase. Typically, such a defect is not considered a breakdown and the TV cannot be returned or repaired.

Such screen defects are called banding, glare and tint..

Tint can be translated as “color tone” and it shows how correctly the white color appears on the screen. While viewing regular video you may not see this defect, because the picture is constantly changing. But if the picture is static, then the interference can be very noticeable and interfere with normal viewing.

To identify tint, you need to apply a white or gray field to the screen. Interference in the form of stripes, spots and other shapes, painted in a different tone, on a uniform background may indicate the presence of a tint defect. Such interference is usually pink or greenish in color and located towards the edges of the screen.

If the defect is very noticeable, then it is better to choose another TV.

The tint is large and clearly visible Acceptable level interference tint

Banding appears on the screen as stripes of a different shade. When watching regular TV shows, it will be noticeable in uniform areas when moving the camera. To identify this defect in a store, apply a uniform field of any color (gray, green, purple) from a flash drive to the screen.

Invalid banding level

Lights can only come from LED TV ov. To assess the quality of the display by the level of glare, you need to do this in a completely dark room (turn off the lights and curtain the windows). In this case, you need to select the maximum backlight level on the TV; for this you can select the appropriate mode (it can be called “bright”, “dynamic” or something else). You need to disable modes that improve the image, such as dynamic backlight, black level adjustment, eco-sensor and others. This is done so that the TV does not adjust the backlight when checking.

But even with this, errors may occur due to the automation of the television receiver when a completely black frame is supplied. After all, when the picture is black, the TV turns off the backlight. Therefore, to detect highlights, it is better to submit a black picture with some bright elements, for example, white titles on a black background at the end of the film.

Then, from a distance, look for screen glare, especially in the corners. Some minimal glare is quite acceptable for normal viewing.

Unacceptable level of glare

It is unlikely that you will be able to find an LED TV completely free of these defects (tint, banding, glare), but you need to choose a model with a minimum level of these interferences.

This article will tell you how you can fix a stuck pixel on your LCD monitor that has stopped changing colors. The pixel usually gets stuck on some color other than black or white, and the problem can often be fixed in a couple of different ways. If the pixel turns out to be broken and not stuck, then it will be impossible to fix it. Likewise, although you have a chance to fix a stuck pixel, it cannot be guaranteed that you will successfully fix it.

Steps

Part 1

Preparing for work

Make sure that the pixel is really just stuck and not broken. Although the terms “dead” and “stuck” pixel are often used interchangeably to refer to problematic pixels, stuck pixels can be fixed, while dead pixels cannot. If the pixel has specific color, other than black, or incorrectly changes its color depending on background color It's most likely just stuck.

• Dead pixels usually remain white or black no matter what is happening on the screen. Even though white dead pixels are sometimes called “hot”, they are not fundamentally different from black dead pixels.
• If you find a dead pixel on your monitor, you will need to either have it repaired or have the screen replaced. Also, sometimes (but not always) dead pixels are covered by the manufacturer's warranty for replacement of the device or its screen.

1. Understand how pixels work. Pixels reflect combinations of red, blue and green colors depending on what is shown on the screen. A pixel can become stuck for a variety of reasons, including using the monitor for too long or after a long period of displaying overly saturated colors. When a pixel is stuck, it displays only one color, which may vary slightly depending on the color of the surrounding pixels.

   • Again, a dead pixel never changes color regardless of the state of surrounding pixels.

2. Check the warranty terms for your LCD monitor. Often, manufacturers are willing to replace a monitor when it has a certain number of stuck or dead pixels. If your monitor is still under warranty, it is best to take advantage of a warranty replacement rather than trying to fix the problem yourself.

   Turn off the monitor for 24 hours. If the pixel got stuck recently, then the problem may disappear by itself - just turn off the monitor for a day. There's no guarantee that you'll fix your monitor this way, but a stuck pixel often means the monitor has been in use for too long and it's best to unplug it for a while to prevent further damage.

   • Completely unplug the monitor.

3. Consider having your monitor repaired. Even if the monitor's warranty has already expired, paying for professional repairs will be cheaper than buying a new monitor due to an accidental breakdown of the device as a result of DIY repairs.

   Know that the pixel can work on its own. It is not uncommon for stuck pixels to disappear after some time, however, this period can vary from a few days to several years. If you only have one pixel stuck on an expensive monitor, it is best to refrain from tapping, rubbing, or otherwise physically pushing the monitor to fix the pixel.

   Part 2

   Using software to fix screen problems

   1. Understand how this method works. Screen repair software displays random combinations of red, green and blue at up to 60 flashes of color per second to return the pixel to its normal cycle.

      • There is no guarantee that screen repair software will successfully fix the problem, but it is usually effective in more than half of the cases.
      • There are both paid and free programs for restoring monitor screens. However, free programs are just as effective in repairing pixels that can actually be fixed.

   2. Avoid using stuck pixel repair software if you have epilepsy. Since this software displays random flashes of rapidly changing colors on the screen, you may want to avoid using it if you (or anyone in your family) have epileptic seizures.

      Visit the JScreenFix website. Go to http://www.jscreenfix.com/ in your browser. JScreenFix is ​​a free online application that can fix stuck pixels.

      Scroll down the page and click on the button Launch JScreenFix to launch the application. This button is colored blue and is located at the bottom of the page. It allows you to open JScreenFix in your browser.

      Find the stuck pixel. The main part of the screen will be black, so you can easily find the stuck pixel.

      • If the pixel is not located in the black area of ​​the application window, press F11 to go to full screen mode. You may have to hold down the Fn key first to press F11 if the browser doesn't go into full screen mode when you just press F11.

   3. Move the flashing repair block of the application to the stuck pixel. Click and drag the flickering block onto the problematic pixel, then release.

      Leave the application running for at least 10 minutes. In this case, do not roll up the window, move the repair unit, or turn off the monitor.

      • If possible, leave the application running for a full hour.

   4. Check the pixel status. When the required amount of time has passed, close the application window to check the pixel. If the pixel is restored, then the problem is solved.

   Part 3

   Applying pressure and heat to the problem pixel

   Understand the risks associated with this method. Although some people have been able to fix stuck pixels with pressure or heat using this method, you are more likely to damage your monitor screen than to repair it.

   • Another problem with this method is that it voids your warranty.

   1. Turn on your computer and LCD monitor. For this method to work, you must turn on the monitor.

      Open the black image. It is critical that the screen actually shows a black image and not be in a no-signal state, as you need the LCD monitor's internal backlight to work.

      Find a thin object with a narrow, blunt end. You will need a marker or a pen with a pointed cap, a very blunt pencil, a plastic stylus, or the back of a makeup brush.

      • Before moving forward, please read the warnings at the end of this article. Physical friction can aggravate the condition of the monitor screen.

   2. Wrap the end of the selected item with a napkin. This will protect the monitor from scratches.

      • If an object can pierce a napkin, then it is too sharp. Find something else.

   3. Use the rounded end of an object to gently press down on the stuck pixel. In this case, a white ripple effect should appear around the point of contact.

      • Try to press exactly on the stuck pixel without affecting the surrounding area.

   4. After a few seconds, remove the item. If the pixel remains in the same state, you can reapply this method or switch to using heat. However, if the problem is resolved, turn off the monitor immediately and do not turn it on for at least one hour.

      Wet a washcloth with hot water. If possible, heat the water on the stove until the first sign of gas bubbles appears at the bottom of the container (about 88°C), then dip a washcloth into it and soak it in the hot water.

      Protect your hands. To avoid burning your fingers in subsequent steps, use an oven mitt or thick cloth.

      Seal the hot washcloth in a Ziploc bag. This will protect the monitor from moisture. Make sure the bag is securely closed.

   5. Apply the washcloth bag to the stuck pixel. Light pressure through the washcloth should loosen the pixel's contents slightly, potentially aiding in its correction.

      • Never apply the packet to a pixel for more than a few seconds at a time.