Broken pixels on the TV
Tv production technology is constantly evolving. It’s safe to say that we live in a generation of plasma and liquid crystal panels. The well-known bulky cathode ray tube televisions are out of fashion. And this is not surprising, because modern TVs are much ahead of their predecessors, both in performance and in build quality and a number of other parameters.
But as they say, each technique has its drawbacks. In this article, we will discuss an important issue regarding dead pixels on plasma and LCD TVs.
What is a dead pixel on a TV
Simply put, the image on a TV panel is formed from a huge number of colored dots, called pixels. The principle of operation of a plasma TV, of course, differs from the principle of operation of an LCD TV, but the structure of image construction is the same in both cases. Pixels change their color in a predetermined way, as a result, the desired picture is obtained.
Each pixel has its own strict structure. Pixels are made up of three subpixels of different colors. Red, green, and blue can have different intensities and can create any color. Most modern TVs use an active matrix. In this case, each individual pixel is controlled by a special transistor. If the transistor fails, then the corresponding pixel ceases to function. This is called a broken pixel.
Such a pixel looks like a black dot on the screen. A broken pixel of this type can be restored only by replacing a faulty or malfunctioning transistor. This method is poorly suited for ordinary users.
There is another type of dead pixel. Stuck pixel. A characteristic feature of such a pixel is the fact that it looks like a bright spot on the TV matrix. This is due to the fact that the subpixel “gets stuck” in one position and only glows in one color. Pixel defects of this type can be corrected at home using specialized software or by physical manipulation. The question involuntarily arises: why do you need to repair dead pixels on a TV yourself, if there is a warranty service?
The answer is very simple. The production of panels without dead pixels is almost impossible, if you set up production that does not allow such a defect, then the cost of TVs will increase significantly. Therefore, TV manufacturers have adopted specific standards, according to which a certain number of dead pixels on the matrix is not a defect and cannot be repaired. There is a generally accepted state standard ISO-13406. According to this standard, there are three main types of dead pixels, and all panels can be divided into 4 classes. So the types of broken pixels:
1. On a dark background. A white pixel.
2. On a light background. A black pixel.
3. The pixel is constantly lit in one color (problem with subpixels).
First class panels do not allow dead pixels. If there is at least one broken pixel, then you have the right to a warranty panel replacement.
Panels of the second class allow the presence of two defects of the first and second types, as well as five defects of the third type. It would be appropriate to say that such panels are the most common in the modern market. If your brand new TV has a second-class matrix and a couple of broken pixels, then this is not a marriage and do not wait for a replacement.
Panels of the third class allow the presence of five defects of the first type, fifteen dead pixels of the second type and 50 of the third.
And finally, the fourth class has the largest range: 50, 150 and 500 bits of the first, second and third types, respectively.
Check TV screen for dead pixels
For example, if you are looking for black dots, then display a white background. If you are looking for a white point, then display a black background, and so on. If you carefully examine the entire screen, then the dead pixel will be visible to the naked eye. The method is painstaking, but reliable. As the saying goes, everything is in your hands.
There are special generators that display images of the corresponding color. The same can be done by downloading pictures of the corresponding colors prepared in Painte from a USB flash drive to the TV. A similar function can be built into your selected TV model. Ask the seller about it.
Functional is the way to check for dead pixels using programs. But for this you need to first connect a computer or laptop to the TV. Download the appropriate program for checking to your computer and search for defects. I would like to highlight a functional utility Nokia Monitor Test, which will help to detect defects and dead pixels on the TV panel.
Recovery of dead pixels on a TV
The sad news is that black pixels (the transistor burns out) cannot be restored with our own efforts. It’s about recovering stuck pixels. There are several ways, they will not give 100% effectiveness, but it is always worth trying.
The first way is to physically target the malfunctioning pixels. Turn off the TV, and using a cotton swab, very gently press on the area where the dead pixel was detected. A few minutes and stop, turn on the TV and evaluate the result. Repeat the procedure if necessary. This method is intended for LCD panels, mechanical impact can move the liquid crystal and the pixel will begin to function normally. Do not use sharp or sharp objects as this will further damage the matrix.
A more gentle and safer way is to use specialized programs. One of these is located at jscreenfix.com/basic.php. According to the developers of the utility, after 20-30 minutes of using it, the problem with stuck pixels is resolved. If there is no result, repeat the procedure after a few hours. What does the miracle program do you ask? This program changes colors around a dead pixel at high speed, which allows you to programmatically solve the problem.
Go to the above site and click Launch. After launching the program, you will see a window with flickering pixels. Hover it over the area of defects and wait for the results. This program may require a license purchase. But there are other similar utilities.
In this voluminous article, we have covered all the questions regarding dead pixels on a TV. If you do not want to solve the problem with pixels at home, then after finding them it is better to turn to specialized services. Good luck, we hope the article was useful.
Going deeper into the details
It is quite easy to identify a completely inoperative pixel, but a partially defective one is much more difficult. Each pixel is formed from three subpixels (red, green, blue). If one of them stops working correctly, then the dot on the screen will glow with the wrong color. Over, in order to catch the “saboteur”, you sometimes have to tinker. Try to see the ill-fated point, for example, on the 50-inch screen of LG 50UK6510PLB! Fortunately, you don’t have to arm yourself with a magnifying glass: it is enough to prepare a USB flash drive with test pictures in advance that will identify the pest in any color range. Rarely, but still there are pixels that work incorrectly only periodically (when a neighboring point lights up with a certain shade). You can catch them using patterned pictures: with stripes, a grid, evenly alternating shapes. Incorrectly functioning elements will stand out in the general row. For testing a 4K display, this selection of images comes in handy.
Backlight uniformity assessment
Full-screen black fill will help you evaluate the uniformity of the backlight. It is necessary to pay attention to the presence of “overexposed” areas in different parts of the display. Some differences are allowed on LCD TVs, but if white spots are clearly visible on a black screen, this is a reason to look for a more successful copy or another model. As in the case of dead pixels, most manufacturers do not consider this a defect, so it will be almost impossible to exchange a TV based on uneven backlighting.
Detection of colored “spots”
White fill is no less important. Here it is required to assess the presence of colored “spots” on the screen. Most often they look like pinkish or greenish areas on an even white color (the so-called tint). This “coloration”, which has arisen in the matrix, will remain on top of the main image, therefore, devices with such a defect should be avoided. As in previous cases, many manufacturers will not consider the presence of “spots” a sufficient reason to exchange or repair the TV. At the same time, it will not hurt to check for banding, which appears in the form of stripes of a different shade. When watching regular TV programs, it will be noticeable in uniform areas as you move the camera. To identify this drawback, you need to submit a uniform field of any color (gray, green, purple) to the screen from the same flash drive.
Technically, tint, highlights and banding are not marriage or breakage. It is almost impossible to find an LED TV without them. But the intensity of interference can be different. You should choose a device with minimally pronounced image defects.
Despite the assurances of marketers who paint cosmic refresh rate figures in technical specifications, finding an “honest” 100 Hz TV is still difficult today. If before buying it was not possible to accurately determine the model of the matrix and find out its real capabilities, the popular “pencil” test will come to the rescue. To carry it out, you will need to submit a very light picture to the display, preferably white. Then take a pencil or any long and thin object and wave it in a semicircle 10-15 centimeters from the screen. If the individual contours of the pencil are not visible, there is no flicker. If you can see several “pencils”. The manufacturer has clearly drawn a zero to the real sweep frequency, and the flickering of this instance will tire the eyes during prolonged viewing. You can verify the effectiveness of such a test using the example of the Samsung UE40MU6103UXRU 100 Hz display, placing it next to any 50 Hz model.
There is no need to place high hopes on ten-watt acoustics squeezed into the thin case of a modern TV. Of course, the speakers with the Sony Bravia KDL40WD653BR bass reflex sound quite decent for their dimensions, but they cannot promise the level of a home theater. Therefore, it is enough just to check the sound for rattling using high-quality samples. At the same time, it makes sense to test the smoothness of volume control from the remote control along with the instant mute function.
Checking the connectors
Usb ports are simply tested with the same flash drive with pictures to identify dead pixels. If the TV has two or more connectors (like, for example, the LG 43UJ630V), nothing prevents you from checking all of them one by one. If you plan to use Smart TV with a keyboard and mouse, it is better to take them with you. It may turn out that even if the USB connectors are known to be working properly, the existing kit will not be compatible with the TV. Here you have to either put up with it, or find a suitable replacement without leaving the checkout.
The headphone jack can be checked even with a smartphone headset. Its capabilities are quite enough to get a general idea of the performance of the 3.5 mm jack. Well, if you don’t want to bother with the wire, then we take our wireless headphones and test the Bluetooth connection, since modern TVs are equipped with such an interface. And to unfold the 49-inch screen of the Samsung UE49MU7000UXRU hanging on the wall every time you want to watch a movie with headphones is a dubious pleasure.
Ears on the crown
Upon receipt of the TV package, please check:
Often the list of standard accessories is not limited to the remote control: for example, the Samsung UE43M5513AUXRU is equipped with an angled antenna adapter that allows you to hang the TV close to the wall. In order to avoid unnecessary costs and loss of time, it is better to immediately check if everything is in place. If at this stage everything turned out to be in perfect order, and the body shines from protective films and seals, you can proceed to the main part. Checking for operability.
How to check the TV for dead pixels when buying. 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 100% serviceability. Often on the screen you can observe completely fixed points glowing in one color, which, even with a change in the TV image, do not change their color and location. It is these objects that are commonly called dead pixels. They can be black, white and colored. There are two reasons for these defects: imperfect technology and a common manufacturing defect.
After the failure of the transistor that controls the liquid crystals, black (“dead”) spots appear, indicating non-functioning cells. The subsequent management of these crystals is simply impossible. Such defects are most visible against a light background. Some experts consider it impossible to “cure” them, others argue that with the help of a laser it is possible to partially restore the working state of the pixel.
The second reason is a 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 number of physical manipulations. There are times when broken pixels, after a while, disappear by themselves.
Thus, when choosing an LCD TV, pay little 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 the TV before buying, and protect ourselves from purchasing low-quality equipment.
Pixel what is it
Liquid crystal displays today are not unusual or extraordinary. On the contrary, in addition to televisions, they are present in many devices: computer monitors, telephones, devices, navigators and other similar equipment. Lcd or LCD technology is based on liquid crystals. After passing through the layer of crystals of light from lamps or LEDs, a corresponding picture appears on the screen.
A color TV matrix is a huge number of tiny indivisible rectangular or circular cells called pixels. In turn, each such object consists of red, green and blue subpixels. It is these colors, more precisely, their combinations, that are considered the basis of color television. The simultaneous illumination of all pixels forms a complete image on the screen. Over, the more pixels, the clearer the picture will be. If you look closely at the display, you can easily see the three colored areas of these objects.
Allowable number of dead pixels
|Class||Constantly lit (white) pixels||Constantly not burning (black) dots||Defective subpixels (color)|
|per million pixels|
How to check a TV in a retail network
The picture is formed on the screen by all display pixels. For example, Full HD (1920 x 1080) resolution assumes more than two million dots. Knowing the permissible norms of dead pixels, methods of checking for such defects, it is not difficult to choose high-quality equipment.
The easiest way is to visually inspect the screen from a close distance for the presence of a point glowing in a different color. An ordinary magnifying glass will be a reliable assistant in this test. Detection of black dots, possibly when feeding a white field to the screen. To find the white dots, just make the screen dark. Finding defective color subpixels can be made easier by alternately changing the screen color.
It is important to remember that some defects do not appear immediately, but only after heating the matrix. Pictures in the form of colored stripes, grids, checkerboard fills will also help you quickly find subpixels that are not working properly and stand out from the general background.
Many people today prefer devices of the new generation 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 in 4K, excellent sound, and many additional functions. To check a 4k TV upon purchase, you need to use pictures with the appropriate resolution.
Is it possible to “cure” broken pixels
Often, defects on the display appear already during operation. Black dots, as mentioned earlier, cannot be removed on your own. As for the 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 inaccurate movement not only does not save, on the contrary, it can add troubles.
The second method is to use special programs that are easy to find on the Internet. Badcrystal. Does not always cope with the task at hand, however, it’s worth a try. Practice shows that it removes stuck points within a few minutes or a couple of days. The JScreenFix program is no less popular today. She not only finds a defect, but also eliminates it. Working time from 20 minutes to 10 hours.
What pixel defects are there
Any abnormal pixels visible against the general background are called broken, but this is not entirely correct. Really broken or dead pixels are only those in which the transistor has failed. They do not glow with any color and just remain black, falling out of the matrix grid. Clearly visible on a white background.
Left and right pixels are frozen, in the center. Broken / digital-boom.Ru
There are also frozen or stuck pixels. These are red, green, blue or white dots that are clearly visible on a black background. They occur when subpixels freeze when updating color.
How many dead pixels are allowed
It seems logical to replace a computer monitor or TV with dead pixels, but manufacturers do not consider the latter to be a factory defect. When you contact the service with a similar complaint, you will most likely be denied service.
Dell Dead Pixel Policy / dell.com
Different suppliers have their own standards for the number of defective pixels, depending on their location, resolution and display diagonal. So, LG considers up to 10 stuck and 3 dead pixels on 20-inch screens to be the norm. Samsung has 7 pixel bits for monitors, while Dell has 1-6 stuck and 6-13 bit pixels, depending on the display line.
How to remove dead pixels
Since black pixels are the result of damage to the transistor, they cannot be repaired without replacing these components. And this is almost unrealistic even in laboratory conditions. The situation is different with colored dots, which appear due to freezing subpixels. You can try to remove them.
How to check a monitor or TV for dead pixels and get rid of the problem
You will need a free app, a Q-tip, and a little patience.
What are dead pixels
In all LCDs, an image is formed from a grid of pixels. They consist of three separate subpixels of red, green and blue, which are responsible for the full color image formation. Each subpixel has a transistor that controls it on and off.
It looks like a broken pixel on the screen / overclock.Net
Even the matrix of a conventional HD monitor contains over 6 million subpixels, and in 4K displays their number reaches 37 million. With such a huge number, some of the transistors can malfunction. Then certain subpixels remain on or, conversely, off.
1. Program method
The method consists in the cyclic output of rapidly changing images, which, due to frequent color changes, increase the chance of returning the hung pixels to the ability to switch again.
There are many options for implementing this method through utilities, online services, and even YouTube. They can be used on a computer, as well as on a TV when connecting a PC with an HDMI cable.
- Bad Pixel is a professional paid utility for Windows, the creators of which promise to remove defective pixels in just 10 minutes.
- Deadpix is a universal program for Windows and Android that helps you find and then fix problem pixels using color cycling.
- Pixelhealer is another utility for Windows. Eliminates stuck pixels with fast flickering RGB colors.
- Jscreenfix is an online service to run on computer, TV and mobile devices. Outputs an area with digital noise that can be moved to the desired area of the screen.
- Pixelfixel is a 12-hour YouTube that is suggested to run and leave overnight. Attention! The colors change at a very high rate and can cause an epileptic seizure. Do not look at the screen, but rather turn it to the side.
The topic is very relevant and in demand. Indeed, until now, hundreds of people having correctly chosen the diagonal and already going for the long-awaited purchase, do not know that they can get a big disappointment due to the fact that they did not immediately notice this moment.
Quite often, on forums on the Internet, you can see the outraged arguments of users that they were refused to return the TV, with broken pixels found already at home.
Perhaps someone will now say that there is a consumer protection law and the like. Yes, that’s all true. But the most interesting thing in this dispute is that people were denied absolutely on a legal basis.
In fact, everything is simple. See, according to the ISO 13406-2 standard, all displays are divided into four main classes, depending on the number of defects allowed. Here is a table for your reference:
In order to more specifically understand what these types of defects No. 1-2-3 are, you need to carefully study the screenshot below:
From this one can only conclude that only displays of the first class can be completely free of defects. But, as far as the author of the article understood, those are installed only on premium expensive TV models.
Over, this is quite simple to do. And if you read this article to the end, you will find out what other parameters can and should be tested when buying your future pet.
So let’s move from words to deeds.
In order to determine the presence of dead pixels on the display, you need to first download special pictures to the USB flash drive. They are images of a uniform color: white, red, black, blue:
For example, this is how the defective area looks like in the picture with a black background:
Just don’t think that the author of the article has dead pixels on the TV. In this case, a special image was launched for clarity. # 128578;
Sometimes there are cases when the seller refuses to launch something from the buyers’ carriers, motivating this by the fact that there is a possibility of damage to the device. Like, you never know what you slip him there. And the administration prohibits.
Let’s see how this can be done on a Samsung Smart TV E-series. I think that by analogy, you can do the same on LCD panels from other manufacturers.
To do this, download any full-size (1920 x 1080) movie trailer, for example this one and play it. If the picture is not expanded to full screen, press the “P.Size” button on the remote control several times.
Then you need to press the “TOOLS” button and select the “Image Mode” item in the “Service” menu that opens:
Now click all the available modes: dynamic. The picture should be brighter, the movie. Paler image and so on. At the same time, the switching itself should pass clearly, without visible distortion.
The same can be done with sound. To do this, select the “Sound Mode” option:
Here, in the same way as in the case of the check, change the modes and make sure that at this time the sound does not disappear and there is no extraneous noise.
That’s all the wisdom, in principle. We have reviewed the main points. What else to say? Perhaps I missed the point about the so-called flashing of LED displays.
Highlights are white patches of light against a completely black background. In order to see them, you need to run the first picture from the image archive (black), with which we checked the TV for dead pixels at the beginning of the article:
In this case, the room should be dark and the TV should be allowed to run for 15-20 minutes before the start of the test. In other words, it should “warm up” slightly. The picture mode recommended for this test is “Cinema”.
On the other hand, there are currently no standards in terms of exposure. This is a side effect of LED technology, which is present in absolutely all manufacturers. So don’t worry too much about this.
We talked about this technology and all the nuances in detail here. About what to do if the device was brought from abroad, they wrote here. Read the links very carefully to understand the essence of the issue.
For dessert, I suggest watching a in which our Belarusian guy literally blew up the hall with his performance at one of the music shows. This is a very catchy and striking performance. Don’t believe me? See for yourself.
Why not a warranty case
In general, a certain number of dead pixels are allowed. This is explained by the fact that the matrices are quite complex and laborious in production. Few manufacturers are able to provide it. However, the defect can be detected when the TV is fully assembled. If manufacturers filter out all products with a defect, even an insignificant one, then the cost of TVs will increase significantly. Therefore, a balanced decision was made:
- All companies that produce TVs maintain the production at the proper level, but do not increase the cost either;
- Buyers agree with dead pixels, but have the right to test the display before purchasing.
There is no deception, the buyer has every right to check the purchased device. If he didn’t, he can only take offense at himself.
We put in physical effort. In this case, you need to gently massage the damaged area with a cotton swab or eraser on a pencil. To do this, we find all the defective points, turn off the TV and make circular movements in the right place. However, even doing everything correctly, the desired result may not be achieved, but it is quite possible to damage neighboring elements.
How to remove dots manually
How to check yourself
For the test, you will need a regular flash drive, you need to throw off monophonic images on it. White, black, green, etc. You need to start checking after the TV has been running for several minutes, since defects appear only on a heated matrix.
To start checking for dead pixels on the TV when buying, ask the seller to insert a previously prepared USB flash drive into the TV. Then display the images. So, on a white screen, dark pixels will be clearly visible, and on a black screen, you can see white dots.
Special testing programs are also available. There are a lot of them, but most often they are used:
Dead Pixel Tester.
Free application for a computer on Windows 7,8,10. The site also contains detailed instructions for checking, which is very convenient.
A site that has 9 color pictures that can be opened in full screen both on a TV / computer and on your mobile phone.
Another program with many settings and high resolution pictures for tests.
The easiest site to use. Everything is very simple, there are the names of the pictures, click on each of them and make it full screen.
In terms of application, the second application is simpler, and it was developed specifically for testing LCD screens. Highlights any area of the display in the desired shade. As a result, all defects can be quickly detected.
If you do not know how to check the TV using these programs, follow the instructions on how to connect a laptop to a TV. By doing this, you will be able to transfer the image from the computer to the TV screen.
What is a dead pixel
First you need to figure out what a pixel is on a TV screen or computer monitor. A pixel is a kind of grid of cells that form an image. Each pixel is made up of three sub-pixels. Red, green and blue. Each color is controlled by a separate transistor, which at a certain point in time turns it on or off, thereby creating the picture that we see.
Even the simplest display has at least six million subpixels, and 4K displays can go up to 37 million. Such a number of transistors can fail, then any of them, when you need to turn on, it turns off. And vice versa. A dot appears on the screen that stands out noticeably. This is a dead pixel.
We use software. For this, applications are used, there are both free in the public domain and paid.
The program is paid, but the developers claim that after its launch, you can eliminate up to 90% of all defects on the screen in a few minutes.
In which colors change at high speed for 12 hours. It is recommended to turn it on at night, but you should not look at the screen as there is a possibility of causing an epileptic seizure.
A universal program that can be installed on both a computer and a smartphone. The site has detailed instructions for installation and configuration.
The site on which you can run the setting online. You can manually specify the damaged area of the screen and start treatment.
Checking the TV for dead pixels. How to fix a defect
How to check
To check the screen for defects, you need to successively submit pictures of the primary colors to it, and at the same time look at it carefully, trying to find points of a different color. This is what broken pixels look like. For example, when there is a white picture on the screen, it is easy to detect black and colored dots. If the color is black, then it is easy to find white points, etc. Before the test, with the TV turned off, make sure there are no dust particles or other debris on the screen.
Why are some dead pixels allowed? The fact is that the technology for the production of LCD matrixes is very complex, and not even every device manufacturer can afford their own production. And such a defect can only be detected on the assembled device. If the manufacturer scraps screens even with minor defects, then the price of TVs and monitors will increase several times. Therefore, such a compromise was found:
- Manufacturers keep production at the same level and do not raise prices.
- Buyers allow the presence of a certain number of dead pixels, which is not a warranty case. In this case, the buyer has the right to check the display before purchasing.
How many dead pixels are acceptable? The answer to this question is contained in the international quality standard for LCD TVs ISO 13406-2. It identifies 3 types of defective points:
Open or white. Such pixels freeze in the open state and constantly glow white.
Also LCD devices are divided into 4 classes. The first class is the highest, the presence of defective points is generally not allowed in the matrix of devices of this class. The bulk of devices on the market are second class. The standard defines the allowable number of different types of defective dots depending on the maximum resolution it supports. Information for popular 2nd class devices is shown in the table below.
|Pixel type \ max resolution||1280 × 720 (720p, HD Ready)||1920 × 1080 (1080p, Full HD)|
Test the screen for dead pixels yourself
When buying a TV or monitor, sellers offer to use an additional service. Check for dead pixels. Over, the service is paid, costing from 500 rubles and more. If you find a defect at home, you will no longer be able to return the TV back, they explain. After all, this is not a guarantee case, and they are right. In fact, you can perform such a matrix test yourself and for free, there is nothing complicated about it. It is enough just to bring with you on a flash drive a special one or pictures for verification, having read our article before.
There are several methods for recovering dead pixels found during the test. They give a result extremely rarely and only in the correction of colored dots (type 3). Tests also show that it usually helps for a short time, the next day the pixel fails again. Plus, you can easily mess up neighboring points. Therefore, we highly discourage recovery, but we will still consider the methods:
- Programmatic approach. A matrix picture is displayed on the screen, in which dots of different colors are displayed randomly. The problem pixel should be restored within 20 minutes;
- Mechanical approach. Turn off the TV, press the broken pixel with your finger through the napkin, turn on the device and stop pressing. This method can harm the matrix.