Despite the fact that the production of LCD panels does not stand still and is becoming more and more perfect, checking an LCD TV for dead pixels is still relevant today. At one time, I already had a negative experience of acquiring a liquid crystal display with a broken pixel, though it was installed in a camera, and not in a TV, but this generally does not change the essence of the problem. In that already distant time, I was overly trusting when choosing digital devices and often relied on the advice and recommendations of sales assistants. And in vain...
So one day I bought a digital camera and returned home with boundless joy from the purchase, and in the process of shooting I found a red dot on the display, which was noticeable only on a black background. Yes, dear reader, this is how a broken pixel proved to be. I will no longer take your precious time and describe how I managed to solve this problem.
Let me just say that the girl (sales assistant) knew about this defect and deliberately showed me the quality of the shooting by pointing the lens at the goods standing on a light background ... Fortunately, I managed to return it to the store with a fight and take my money. Since then I have learned a lot and now rely only on my knowledge and strength. Of course, there are honest and competent sales assistants, but unfortunately the vast majority of them think only about how to "shod" the buyer or how to cram some product, and not about how to develop professionally and be really useful to the consumer.
Indeed, sometimes it is very problematic to get high-quality advice from them, they carry some kind of nonsense considering you for a fool ... Yes, and managers treat this very negligently and do not think that the sales assistant is the face of the company and it depends on his quality of service whether he will return the buyer to their store or bypass it on the tenth road.
In one of my publications, I already wrote about (in detail about how 3D works on TVs) and how to choose the right model for yourself with the necessary functions. And now, at the request of blog readers, I’ll tell you how to check an LCD TV for dead pixels. I think I need to first briefly tell you about what pixels are, so that you have an overall picture of the operation of the LCD panel.
I want to make a reservation right away that the information I have provided about LCD technology will be of a general exploratory nature, because, firstly, in this publication we do not consider the creation of liquid crystal displays, and secondly, in order to convey to you all the details of the production of LCD panels, you need to write a separate article.
What is a pixel in a TV?
Creating an LCD panel is a very complex process and there are many technologies for reproducing information based on liquid crystals. Liquid crystal displays are used in almost all digital devices (computers, TVs, cameras, telephones, navigators ...) and today life without them is already unthinkable. All these digital devices with LCD technology have firmly entered our lives, and with them came the problem of paramount importance - dead pixels.
LCD technology is based on liquid crystals, through which light is passed to produce an image. Most often, the outer layers of the LCD panel are made of glass, and already between them and the polarizing filters are placed a thin-film transistor, a color filter panel, a layer of liquid crystals with a typical backlight module inside (back, side ...). During the operation of the TV, light passes through a layer of liquid crystals and the viewer sees an image of pixels painted in different colors.
Each pixel is made up of three sub-pixels (red, green and blue) that allow the liquid crystal display to recognize millions of colors and shades. The molecules of liquid crystals behave like molecules of a liquid substance, being constantly in motion, but as it should be for crystals, their orientation remains unchanged. Orientation changes only under the influence of an electric field.
Pixel- this is the smallest element of a digital image or display matrix, which is an indivisible object of a rectangular or round shape and forms an image on the screen.
As soon as this condition begins to be fulfilled, the substance in the form of liquid crystals begins to change orientation, up to a selective change in the subpixel. Crystals here play the role of optical lenses that change the polarization of light waves. Each pixel in the liquid crystal panel works according to this principle.
Causes of dead pixels.
Modern TVs usually use an active matrix, and the number of pixels in liquid crystal displays is simply huge and it is simply impossible to guarantee the health of each of them. In order for a broken pixel to appear on the TV, it is enough for the control transistor to fail or the subpixel to get stuck in one position.
In the first case, it will not work to restore black dead pixels (a non-working transistor) on your own, without the appropriate skills and equipment. I once read that in the factory, you can simply burn out a damaged transistor with a laser. Of course, such a pixel will not be able to return the working state, but it will be less noticeable to the human eye. I don’t know how true this is ... Perhaps there is another more affordable solution for restoring this type of broken pixel, but I think that such a defective pixel cannot be “cured”. This type of dead pixel looks like a black dot and will be especially visible on a screen with a white and light background.
In the second case, a broken pixel defect can be eliminated programmatically or by physical manipulation at home. This dead pixel defect is called a "stuck pixel" and it appears as a light or colored dot on the screen. And this is due to the fact that the subpixel is stuck in one of the positions and glows in one color on the display. How to remove such dead pixels, I will tell you further. By the way, sometimes broken pixels that appear can disappear on their own after a while.
The causes of dead pixels can be both a manufacturing defect and an imperfect technology. Yes, dear reader, nothing is perfect in this world. It must be said that there are standards regulating the number of acceptable matrix defects (broken pixels) in the presence of which a digital device will not be recognized as a marriage. So you can’t return it under warranty or how to return it to the store. Therefore, be sure to test the TV for dead pixels when buying.
Permissible number of dead pixels.
Determined allowable amount dead pixels on a liquid crystal matrix using a special specification ISO 13406-2 (in Russia - GOST R 52324-2005). It should be said that this document contains about 150 pages and regulates not only defective pixels, but also defines a number of other requirements such as the degree of reflection, the level of brightness and contrast, text readability, fill factor, uniformity of backlight and color fills, flicker and glare ...
Nowadays, all famous brands and manufacturers adhere to the ISO 13406-2 standard, because the creation of a liquid crystal matrix is a very expensive and time-consuming process, and it is possible to test the assembled panel for defective pixels only after complete manufacturing. In this regard, manufacturers try to reject such products as rarely as possible, classifying them after the test to one of the four quality classes. The ISO 13406-2 specification itself defines four classes (class I, class II, class III, or class IV).
Permissible number of dead pixels per million according to ISO 13406-2.
- 1st class: does not allow pixel defects (expensive and rather rare models on our market, and if there is at least one broken pixel, you are entitled to a warranty replacement of the LCD panel).
- Class 2: Allows for 2 defects of types 1 and 2, as well as 5 defects of type 3 (the most common class of LCD panels in our market).
- 3rd class: 5 defects of the 1st type, 15 of the 2nd type and 50 of the 3rd type are allowed.
- 4th class: 50, 150 and 500 defects of types 1, 2 and 3, respectively, are allowed. (There are practically no such products among mass production).
Types of dead pixels.
- Type 1 - white pixel on a black background;
- Type 2 - black pixel on a white background;
- Type 3 - colored (red, blue, green). This is usually a problem with subpixels.
To make it more clear to you, I compared the defective pixels according to the table.
By the way, the class of products directly affects its cost. For example, a smartphone from one manufacturer costs 800 €, and a smartphone from another manufacturer that is superior in all respects can cost a third less.
How to check your TV for dead pixels.
In one of the publications, I already wrote about how to use well-established programs to check the monitor for dead pixels. Actually, the test for dead pixels on the TV is practically no different and it can be done using the same programs or through a specialized online service on the network (read how to connect Smart TV to the Internet via Wi-Fi, but using a LAN cable). To check the TV through programs, it will need to be connected to the system unit or laptop. But what if we buy a TV with a liquid crystal panel in a store, but we don’t have a computer at hand.
Of course, there are stores that provide a paid service for checking the TV matrix for broken pixels. But why pay when you can do the test yourself. In order to check the TV for the presence of dead pixels in it, you need to display one-color background images on the screen in turn. For example, to find a black point, you need to display a white background on the TV screen, and to find a white point, you need to display a black background on the screen. This is how they look for dead pixels.
So, in order to independently perform a test for broken TV pixels, you need to write to a USB flash drive (how to choose a reliable USB flash drive, and on what principle they work) a set of images with color fills and gradients. I also recommend writing a set of test videos to a USB flash drive that will help you not only conduct a test, but also evaluate the sound quality and the capabilities of the built-in player.
You can download images for testing a TV for broken pixels 1080P (with FullHD resolution 1920x1080) and 720P (with HDReady resolution 1366x768) using the link below. The archive contains two sets that need to be extracted from the archive and written to a USB flash drive.
You can download videos for testing a TV for dead pixels at the link below. The archive contains two videos for testing TVs with FullHD (1920×1080) and HDReady (1280×720) resolutions. The videos contain a set of images of different colors and gradients, which will be sequentially displayed on the TV screen to the music, which will make it possible to simultaneously check the operation of the speaker system.
So, now you are fully armed and you can safely go to the store for the cherished purchase in the form of a TV. Perform the test without haste and carefully look at all parts of the screen, and if there really is a defective pixel, then you will definitely see it. It should be said that it is difficult to notice "dead" and "dependent" pixels. The so-called “dead” pixels are not visible on all color fills, and “dependent” pixels can only be detected on moiré (“checkerboard” and “grid” fills). You can also check the monitor with these kits, but it’s better to use special programs like Nokia Monitor Test (about how to check the monitor for dead pixels).
Repairing dead pixels on a TV.
Nothing in this world is perfect and any digital equipment can fail, and the liquid crystal panel can eventually upset the owner with the presence of dead pixels. What to do in this case? I think you understand that the defective pixels that were formed as a result of the failure of a thin-film transistor cannot be restored on your own. But you can bring the so-called "stuck pixels" back to life. You can try to "treat" dead pixels in a software or mechanical way. But not one of them gives a 100% positive result.
Program treatment of dead pixels.
The first step is to try to bring the frozen pixel back to life programmatically. Usage specialized programs safer than physical treatment. I know about the two most effective and really working utilities. These are Bad Crystal and JScreenFix. Both of these programs are paid, but the price of the issue is not high.
If you are not sure that the Bad Crystal program will help you, then there is a test on the developer's website to assess the chances of recovering dead pixels. Also on the site there is a section with frequently asked questions and utility testing reports, as well as technical support. This is a very worthy and functional program that supports Plasma, LCD, LED, OLED and 3D screens, increases the service life, restores up to 90% of defects, removes a frozen pixel in 10 minutes (in some cases, the process can take about 48 hours) and has a simple and clear interface.
The JScreenFix program is also very popular, which, according to the developers, helps not only to find dead pixels, but in 80% of cases it manages to restore them. The program will guide you step by step until the defective pixels are completely restored. The utility performs high-speed color switching of each pixel, which allows you to return a stuck pixel to work.
The developers claim that the program is able to return everything to normal within 20-30 minutes, and in more severe cases It is recommended to leave the program in operation for 8-10 hours. If there is no positive result, they recommend repeating the process. This software solution also reduces screen burn-in and improves display quality.
Physical treatment of dead pixels.
If the program failed to restore the defective pixels, then you need to massage the TV / monitor. Take a match and wind a piece of cotton wool around it (you can use an ear stick), turn off the TV and start a slow and gentle massage in the area of the broken pixel. Don't press too hard, but circular motion do it with feeling. Thus, by massaging the area with the stuck pixel, you can restore it to the desired position and it will begin to function correctly. If necessary, repeat the procedure.
Just do not overdo it and do not massage the panel with your fingers, and even more so do not touch it with sharp objects, otherwise you will add a dozen more dead pixels to the matrix. It must be said that this type of dead pixel recovery is not safe and you do all the manipulations at your own peril and risk.
This is where I will end the article. I hope the prepared material was useful and easy to understand for you. If you have something to add to the publication or you want to express your opinion, then you are welcome in the comments. Bye!
2019-03-03T22:42:44+00:00
Unfortunately we don't have psychic abilities and therefore we cannot say how long your TV will live. Most likely, the appearance of dark spots on the screen indicates the presence of damaged pixels. Like it or not, they will answer you at the service center, since they will be able to perform a detailed diagnosis and identify the cause that led to the appearance of dark spots. If the service center confirms that the matrix is really damaged, then the feasibility of repair will most likely have to be questioned, because the replacement price, plus or minus, will be comparable to buying a new TV. P.S. By the way, such spots could appear as a result of mechanical or high temperature exposure. If such stains were found after purchase, then return it to the seller under warranty.
2019-03-03T17:14:14+00:00
Good afternoon, not so long ago I noticed that on a TV (samsung series UE48 ....) dark spots are visible on a light background, as far as I understand, the backlight diodes or a burnt-out matrix in the places where the diodes are located, if you focus your eyes, you can see (grid ) vertical and horizontal lines for placing backlight diodes, generally dark spots. Tell me what does this mean? How long will the TV live and how is it treated?
2018-08-26T18:31:45+00:00
Could you attach photos to the comment to try to evaluate visually.
2018-08-26T16:54:15+00:00
Please tell me, I recently purchased a TV and with certain colors, usually blue / blue, in those places where these colors predominate, a contour of green dots appears, there is no contour on other colors, I could not characterize this problem as dead pixels, this is something other. These green points are chaotic and not tied to a place, they are tied only to the area where certain colors predominate.
2018-06-17T19:55:36+00:00
In Yulmart, they returned the money to me for 1 broken pixel without question. They connected it in front of me, they saw it, they even wrote an application for a refund for me. If the packaging is not broken and there are no defects, you can return the aircraft within 10 working days. Putin signed this amendment to the RFP law a long time ago, stating that any product, including previously related to complex equipment, can be returned by the buyer, regardless of the method of purchase, that is, in a store or via the Internet. And all the brave and semi-literate managers or sellers, we are waiting for the buyers in court) Only the amount after the trial will be different)))
2017-07-29T13:20:48+00:00
Thank you very much for the information)))
2017-02-15T18:51:52+00:00
Hello. Tired of choosing. Maybe you can advise. TV LG 55UH850V and TV Samsung UE55KU6000U. Is it worth it to overpay for this LG? Two criteria are important - image quality / price. 3d doesn't matter. The price difference is 30k.
2017-01-31T20:01:25+00:00
Good evening. Article class. Thank you. I want to buy a TV for 110 thousand rubles, but I don’t know what class it belongs to, 2 or 3? The first one I don't think so. There's probably a TV should cost over 150K.
2016-09-13T20:52:59+00:00
Unfortunately, I don't have a constructive answer. However, if you are no longer happy with the purchase, then try to return it. If you don't, you will most likely regret your choice later on. Good luck!
2016-09-13T20:48:11+00:00
Thanks for the answer. But I am tormented by the question - is such a transition in gray shades (from brown through green to gray) considered normal (permissible) in such displays?
2016-09-13T20:40:35+00:00
If two weeks have not passed since the date of purchase, then you can legally return the device under any pretext, if the presentation of the smartphone and packaging is preserved. P.S. There is an acceptable number of dead pixels so that the device is not considered a marriage. Return or not, it's up to you. Good luck!
2016-09-13T20:36:31+00:00
Thank you. Good article. I checked the smartphone FWVGA 854 x 480, TFT LCD, 4.5", 24-bit, instead of dark gray shades, green and brown colors are displayed, instead of light gray, a solid color is flooded. Please tell me, is this normal or take it back to the store? store then how to characterize it?
2016-09-12T23:55:29+00:00
2016-09-12T23:18:11+00:00
Hello. Please tell me, is it possible to check the screen of a smartphone 854 x 480, 4.5" with this video?
2016-06-08T17:00:05+00:00
VERY HELPED. CHECKED YOUR TV AND MONITOR. EXCELLENT ON TV. AND ON THE MONITOR I FOUND 4 DEAD PIXELS... IT IS SEEN ON A BLUE BACKGROUND AND RED.
2016-04-04T15:38:07+00:00
You can use NTFS.
2016-03-31T17:51:41+00:00
Good afternoon. In what format should I format a flash drive to check for pixels?
2016-03-07T11:03:23+00:00
Thanks, the article helped.
2016-01-17T21:54:12+00:00
Hello! Is it possible to upload pictures again to search for dead pixels? You can’t download them from Yandex ... I downloaded the video, checked the TV. I knew that there was one dead pixel and where it was. green. It is not visible on red and light colors .... Thanks for the video, if you can re-upload the pictures
2015-04-21T01:43:39+00:00
The other day I bought an LCD TV, model: Sony KDL-55W828B, after a few days I noticed white dots numbering 10 - 15 pieces, they appear from time to time, but quite often they appear mainly when watching the movie "Once Upon a Time in Rostov", I don’t know why exactly in this film. When watching other channels, everything seems to be normal. I downloaded the test with different backgrounds, the result, I don’t see a single white dot, everything seems to be perfect, but in the film, I see them clearly, one at a time and even in pairs and three cells at a time. Frankly, I'm at a loss. Can you advise something? I will be grateful!
2015-04-15T14:06:22+00:00
Good advice! There was a strip in the middle of the screen a little rubbed with a cotton swab, it disappeared. I thought the master's garbage should be called, but I decided to try it turned out
2014-12-08T16:30:18+00:00
Oleg: Now everything is clear. I wonder how the mote with inside glass turned out? :) Since the point (or whatever you have there) is no longer visible from such a distance, then ... You know better: "Let it be" :) Good luck!
2014-12-08T16:13:35+00:00
Dmitry: noticeable on all colors except black :) It looks as if the rubber sheet of pixels was pulled back a little behind this point. Maybe a speck on the inside of the glass got in. It does not cause discomfort, as it is visible from a distance of ≲ 30 cm. Let it be. Thank you.
2014-12-08T14:17:37+00:00
Oleg: Most likely, this is still a defective pixel, but I'm not sure. Is it necessary to be afraid of it? If this does not cause discomfort to you, then there is nothing to be afraid of. Is the spot noticeable on all colors or on some specific ones?
2014-12-08T13:54:23+00:00
Dimitri: One. There were two, I rubbed one, it turned out to be a speck of dust. Ter-ter, does not leave. But it is noticeable only if you know where it is and look close.
2014-12-05T16:10:26+00:00
Oleg: I quote: "Darker than the rest on a black background" And how many of them do you have on the screen?
2014-12-05T15:30:53+00:00
JPEG pictures are lossy compressed. There is a bunch of colored noise around the one pixel thick tex. I got scared when I saw it on TV. I will make clean pictures based on yours. I have a question about dead pixels: there is a spot on the TV that is darker than the rest on a non-black background, it is noticeable up close, in size and location it seems to not fall into the outline of the pixel (a little smaller, its borders are blurred). What could it be? Is this something to be afraid of?
2014-11-10T23:23:47+00:00
Dmitry: I suppose that the question was about "Demo mode" or "Shop" mode and should not affect the check with broken pixels. The other day I myself want to buy a smart TV 47-50 inches with a price of up to 50 thousand rubles, personally, such a defect would have plunged me into horror!
2014-11-03T13:04:23+00:00
Pavel: These images are not for tuning, but for testing for broken pixels and nothing more. Get it right. Questions should be asked on the topic of the article. After you, the comments will be read by people who came to get information on dead pixels.
2014-11-02T16:08:57+00:00
Clearly, this is not about my TV ... there are also different test pictures, so I thought that somehow they could help set it up correctly ... Everything is already in the past, I set it up a long time ago, and everything suits me. Good luck to all!
2014-11-02T13:31:11+00:00
2014-11-02T13:22:38+00:00
Pavel: Dmitry thanks for the article! Everything seems to be clear with broken pixels, they should be immediately visible, unless of course they are .. but here's how to do it correct settings, revealing all the capabilities of the TV (sony 55w955b), using color and multi-colored pictures, I do not understand. If it's not difficult, please tell me. I would be very grateful, thanks!
2014-08-24T10:33:09+00:00
Dmitry thanks for the article! Everything seems to be clear with broken pixels, they should be immediately visible, if of course they are .. but I don’t understand how to make the right settings that reveal all the capabilities of the TV (sony 55w955b), using color and multi-colored pictures. If it's not difficult, please tell me. I would be very grateful, thanks!
2014-08-21T17:23:43+00:00
Roman: Firstly, I did not call anyone scoundrels in the article. No need to lie. Secondly, there is a list of goods for which a return cannot be made ... However, there are footnotes in other articles that the court refers to when making a decision. That is, each case is individual and it is impossible to say for 100% that the goods cannot be returned. It all depends on the specific situation. And in your opinion, it turns out that you can shove equipment to buyers with impunity. Some buyers know how to check equipment for defects, while others do not. Here are some people who use it. I emphasize some. Thirdly, one dead pixel is not a marriage in relation to Smart TV (we read the article and look at the table). It all depends on the standard and class. The 1st class does not allow the presence of dead pixels at all, but in our country such digital devices are still rare. Therefore, while one pixel is not considered a marriage, no one wants to have such a Smart TV. Unless they buy it at a discount. You first read the article ... Fourthly, why write to me in the comments the entire 25th article. My post is not legal. It is freely available, go and read. Fifthly, I wrote in Russian that there are very competent and honest sellers. Sixthly, I do not call in the article to return the goods if a broken pixel is found on it, but I call on buyers to be vigilant. For then buying instead of joy can lead to disappointment. Seventh, you are probably the negligent seller who does not take the side of the consumer. Sellers who value their customers work on the principle: "The buyer is always right" and always go to a meeting. I consider this dispute pointless, I am busy with work and I have neither the time nor the desire to respond to your comments.
2014-08-21T11:21:33+00:00
Why don't you send me the article to the end. I don't want to argue with you in any way, I just want to explain. You yourself wrote that the sales consultants are still the same, well, get a return to your karma from me. You shouldn't have written like that in your post. 25th article. End of Article 1... "The list of goods not subject to exchange on the grounds specified in this article is approved by the Government of the Russian Federation" It turns out that there is a certain list according to which goods cannot be exchanged ... List (list of non-food products of good quality, NOT RETURNABLE AND EXCHANGEABLE for a similar product ....): Item 2 (for example) - personal hygiene items Item 6 (for example) - items in contact with food ... not just a frying pan. but also a kettle and even a microwave Item 11 - Technically sophisticated household goods One pixel is not a defect, and you will not change the TV. I'm talking about it. You yourself posted a table on this page where the number of pixels and the class are indicated. There are two articles for which exchanges / returns are made. Article 18 talks about marriage returns. That is, if you turn on the TV at home, and there is a strip across the screen. Article 25, which speaks of the EXCHANGE of goods without defects. Again, 1 pixel is not a defect.
2014-08-21T00:16:39+00:00
Roman: The right of the consumer to the proper quality of products 1. The seller (manufacturer, performer) is obliged to transfer to the consumer products of proper quality, as well as provide information about these products. 2. The seller (manufacturer, executor), at the request of the consumer, is obliged to provide him with documents confirming the proper quality of the products. The seller is obliged to sell a quality product, and he can verify its quality only after a personal check. I know various cases of returning goods from the practice of other people and even through the courts. You read this article to the end and delve into its essence. In addition to the listed product, it has a sequel. Article 25. The Consumer's Right to Exchange Goods of Good Quality However, a refusal to exchange may follow if there are no conditions for the exchange provided for by the Law: the goods have not been in use, their presentation and consumer properties have been preserved, as well as seals, factory labels, a sales receipt or cash receipt. The consumer can exercise his right to exchange a good-quality product within 14 days, not counting the day of purchase. In case of refusal to exchange and disagreement of the consumer with this, he has the right to bring an appropriate claim against the seller in court. In the absence of a similar product on sale at the time the consumer contacts the seller, the consumer has the right, at his choice, to unilaterally terminate the contract and demand a refund of the amount paid for the product or to exchange it when the similar product first goes on sale. The seller is obliged to inform the consumer about this. In this case, the right to exchange is retained for 14 days from the receipt of the message by the consumer. It should be emphasized that the choice of a course of action in the event of a product being out of stock belongs exclusively to the consumer. In addition, it is still full of all sorts of extracts and footnotes from other articles. P.S. There is no connection to check the goods and to increase your salary. You can argue about this for a long time, but there is no point in this. You like to buy goods this way - buy. Your position is clear. I don't have time for empty talk. Good luck!
2014-08-20T23:47:44+00:00
And further. The buyer has the right to inspect the goods. I repeat, THERE IS A RIGHT, and whether he will use this right or not, nobody cares. The law does not write that the Seller is obliged to check the goods. For example, I have the right to demand an increase in salary, and whether it will be increased to me or not, nobody cares.
2014-08-20T23:46:07+00:00
Dmitry: "Within 14 days, the consumer has the right to return the goods without any defects, if the packaging and the digital device have retained their presentation. Even if I no longer like the color of the digital device." And now read again carefully the 25th article and the list of goods that cannot be exchanged.
2014-08-20T12:44:23+00:00
Roman: The consumer pays money and wants to have a quality product... Those who have faced returns of digital defects know that sometimes it is not easy to do this, even if the law is on your side. Within 14 days, the consumer has the right to return the goods without any defects, if the packaging and the digital device have retained their presentation. Even if I no longer like the color of a digital device. It is clear that there is no need to come to this either, and everything should be within the framework of reason. However, often the consumer is refused. You see, there is no reason to return. Who is the law for? The consumer is not obliged to stand over the soul of the director in order to return the goods according to the law, but the seller (shop) is obliged to follow the letter of the law. The point is not only that you need to be more careful when buying, but also that they must check it themselves before selling it and make sure that there is no marriage. However, unscrupulous sellers are silent about this. Ideally, when everything is fair. As a result, the seller will receive money, and the consumer will receive a quality product. And everyone is happy. No one rolls a barrel at anyone, and there is no escape from the facts. I'm all for following the letter of the law. The law is the same for everyone. Good luck!
2014-04-29T15:49:54+00:00
I bought a Sony and found a dead pixel. The store claims that 7 dead pixels are acceptable. If not replaced, it will have to be treated. Article by the way.
2014-03-31T14:04:36+00:00
Salam: Working with a cotton swab is very painstaking and requires skill. But everything is possible ... I am very glad that everything worked out for you. Good luck!
2014-03-31T14:01:25+00:00
Thank you very much, the article helped a lot, I first tried to rub it with a cotton swab, but three more pixels appeared and, most importantly, all of the same color - blue, then I used bad crystal, threw some function from the middle and lo and behold !! all the pixels disappeared in just a couple of seconds! Now I'm afraid to touch the screen...
Question from user
Hello.
I have some kind of white dot in the center on my monitor, and another red one in the corner. The one in the corner - I don't care about it, but in the center - sometimes it annoys and interferes. When a color picture is shown, it is not so noticeable, but with a monochromatic (and especially dark) picture, it does not look very good.
They refused to repair the monitor, they say that you can’t restore these broken pixels (it’s easier to buy a new monitor). Is this true, and is it possible to somehow remove these points, restore broken pixels?
Michael.
Good day!
In fact, one of the common problems with monitors is the appearance of dots on the screen that do not change their color (ie do not work). Most often, they glow with just plain light: white, dark, red, etc. Such pixels on the monitor are called beaten .
In this article I will try to answer both your question and the same type related to this topic. I'll show you how to check your monitor for these dead pixels, as well as a few recommendations that can bring such pixels back to life. So...
To help!
Monitor check: do a test for dead pixels
A few important points
If you think that dead pixels can only appear on old monitors, then you are deeply mistaken ... It's even more annoying when you buy a new large monitor, and then in the process you find that one pixel in the center does not "burn" (more precisely, it burns red) . And what's even more offensive is that you most likely will not be able to return such a monitor back under warranty!
Important!
According to the standard, monitors are divided into different classes (I, II, etc.). Each class is allowed a certain number of dead pixels, and until this number is exceeded - this is not a warranty case!
Therefore, be very careful when buying a new monitor, I recommend that you test it right in the store!
One of the tables with the allowed number of dead pixels is shown below. In general, IV - class is essentially a marriage (and they are not available on the mass market), most often, an ordinary home monitor is a class II or III device. Therefore, for delivery under warranty - you need at least 2-3 dead pixels. This is all to the fact that checking when buying is very important!
How many dead pixels are allowed on the monitor (depending on its class). Important: this plate is just an example, non-compliance regulations change frequently.
And so, now about how to check ...
The essence of the check: you need to fill the screen alternately with different colors: white, red, green, black, etc. With each fill, be sure to carefully examine the entire surface, if there is any point that stands out from the rest. See 2 photos below, they show very well what to look for.
It is best to "fill" the monitor with multi-colored paints using special utilities. One of the most convenient is IsMyLcdOK (more on that below).
With the help of the program IsMyLcdOK
One of the best utilities for checking the monitor for dead pixels!
The utility is very simple and does not need to be installed and configured. It weighs only 36 Kb, and it can be written to any medium. After starting - you just need to press the numbers on the keyboard: 1, 2, 3, etc., or the Ctrl key - and the entire screen will be alternately filled with different colors. All you have to do is watch what is happening.
Thus, using IsMyLcdOK, you can evaluate the state of the monitor in a few minutes. Definitely recommend to use!
The main advantages of the utility:
- small size - only 36 Kb, can be written to any flash drive;
- nothing needs to be installed or configured - just run and press one Ctrl button;
- The utility is free and works in all versions of Windows.
Online way
Monitor Test
A very simple and effective utility that can revitalize (restore) dead pixels. The utility is free, works in all versions of Windows, takes up very little space. In addition, with her work, you can simultaneously go about your business. That is why I fixed my eyes on her ☺.
How to work in it (step by step):
Method number 2: discharge ...
This method can in some cases help restore the pixel. Its essence is to disconnect the monitor from any power source and let stand for several days (recommended 4-5 days!).
If you have a laptop: disconnect from the mains, remove the battery, disconnect all wires going to the device (network cable, mice, speakers, etc.). That's it, leave the device in this state for a few days.
If you have a regular PC monitor: Also disconnect it from the network and from the computer.
If you leave the device in this state for these 4-5 days, then all the capacitors in the device will be discharged, the residual voltage will leave the thin-film transistors. And when you connect the monitor to the power supply and turn it on, the stuck pixel will be shaken, perhaps it will return to "life" (I note right away that this method does not always help, in about 5-15% of cases).
Method number 3: mechanical pressure
If the software method did not help, try taking a cotton swab (or a pencil with an eraser on the end). Then set this wand or pencil approximately in the center of the broken pixel and press lightly (if streaks appear on the screen, remove the object).
If the pixel has not started working, repeat the operation (you can slightly increase the effort). So try doing 20-50 iterations.
Also, try to turn off the monitor completely, then press on the place where there is a dead pixel, and then turn on the monitor. In some cases, a "stuck" pixel wakes up and starts working as expected...
That's all for me, for additions on the topic - I will be very grateful.
If you want to exchange an already purchased monitor with dead pixels, then keep in mind that there is an international standard ISO 13406-2 that regulates the allowable number defective pixels on the LCD monitor. Thus, the seller may refuse to exchange your monitor or refund your money if the number of defective pixels in .
1Permissible number of defective pixels on the monitor
The allowed number of defective pixels depends on the display class (pixel fault class). ISO 13406-2 defines four classes: the first does not allow the presence of defective pixels. As a rule, all modern LCD monitors belong to second class. Below you can calculate the allowable number of defective pixels in accordance with the ISO 13406-2 standard for monitors second class:
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Note. In the calculation, the fractional number of defective pixels is rounded up to an integer by discarding the fractional part.
The ISO 13406-2 standard distinguishes the following defects: permanently lit white pixels (type I), permanently unlit black pixels (type II), sub-pixel defects (type III), which appear as colored permanently lit / non-lit pixels of primary colors (red, green , blue, cyan, magenta, yellow).
In addition, for resolutions of 1 million and above, the accumulation of color defective pixels (type III) is allowed side by side in a 5 x 5 pixel square. Such a defect is called a cluster. Second class monitors does not allow the presence of 5 x 5 clusters with type I or II defective pixels. For more details see.
In practice, such a large number of defective pixels as specified in ISO 13406-2 is extremely rare. The wide tolerance can be explained by the fact that the standard was developed in 2000. Since then, liquid crystal panel technology has improved.
2How to check your monitor for dead pixels
Examination LCD monitor on the presence of defective pixels is to carefully examine the screen for abnormal pixels. Inspection is carried out sequentially for the primary colors: black, white, red, green, blue, cyan, magenta and yellow.
ISO-9241-3XX
The standard defines 4 quality classes for monitors. Class 0, the highest, does not allow for defective pixels. From class 1 to class 3, the number of allowed defective pixels increases.The following types of defects are distinguished:
- 1) Constantly burning pixels.
- 2) Constantly extinguished pixels.
- 3) Sub-pixels (including double sub-pixels) that display a darker or brighter color than desired. (Simply referred to as "light or dark sub-pixels")
- 4) Constantly burning or constantly extinguished subpixels. A lower number in the table means the maximum allowable number of constantly burning subpixels.
| Class | Number of Type 1 Defects | Number of type 2 defects | Number of Type 3 Defects | Number of defects type 4 |
| 0 | 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 2 | 3 - 5 |
| 2 | 2 | 2 | 5 - 10 | |
| 3 | 5 | 15 | 50 | |
ISO 13406-2
The standard distinguishes 4 quality classes for LCDs, each of which allows a certain number of non-working pixels in a million:- Class 1: 0 defective pixels per million.
- Class 2: up to 2 type 1 and 2 defects or up to 5 type 3 defects per million.
- Class 3: up to 5 type 1 defective pixels; up to 15 - type 2; up to 50 defective subpixels per million.
- Class 4: up to 150 dead pixels per million.
- Type 1: permanently burning pixels.
- Type 2: Permanently off pixels.
- Type 3: pixels with other defects, including subpixel defects (the RGB cells that make up the pixel), i.e. constantly burning red, green or blue sub-pixels.
- Type 4 (defective pixel group): several defective pixels in a 5 x 5 pixel square.
Dead pixels and subpixels on TFT matrices of monitors, laptops and TVs, unfortunately, are the norm for display manufacturers, defined by the standard ISO 13406-2
Standard ISO 13406-2 defines 4 quality classes of monitors:
Class 2- the most common and allows no more than 9 defective pixels for every million pixels. Practically all manufacturers' products comply with class 2 and if you come across a product without defective pixels - YOU ARE LUCKY! But be prepared that the luck factor greatly decreases with increasing resolutions and, for example, if you buy a laptop with a WUXGA matrix without defective pixels - YOU ARE VERY VERY LUCKY! If there are 1-5 of them - very lucky.
Class 3- allows the presence of no more than 70 defective for every million pixels of the matrix.
Class 4- the lowest, allows no more than 700 defective ones per million pixels of the matrix. Fortunately, to our knowledge, LCD manufacturers do not release Class 4 monitors for sale to end users through a distribution line.
Class 1- the highest, does not allow the presence of defective pixels, but none of the manufacturers known to us corresponds to this class throughout model range. Recently, however, a series of products from individual manufacturers have begun to appear that do not have defective pixels.
How many pixels are on the matrix?
The calculation is very simple, you just need to multiply the number of lines vertically by the number of lines horizontally.
Examples:
XGA - 1024x768 = 768432
WXGA - 1280x800 = 1024000
SXGA - 1280x1024 = 1310000 etc.
What are pixel defects?
The standard distinguishes 4 types of defective pixels:
Type 1: Permanently lit pixels, visible as a white dot.
Type 2: Permanently lit pixels, visible as a black dot.
Type 3: Pixels with other defects, including defects in the subpixels and RGB cells that make up the pixel. This means permanently lit or flashing red, green and blue pixels. Experience shows that this is the most common defect.
Type 4 (defective pixel group): several defective pixels in a 5 x 5 pixel square.
Now look at how many defective pixels are allowed for every million pixels of the matrix according to ISO 13406-2:
Specific values are given in the following table:
Class | Number of Type 1 Defects | Number of type 2 defects | Number of Type 3 Defects | Number of clusters containing more than 1 type 1 or type 2 defect | |
I | |||||
II | 2 | 2 | 5 | 0 | 2 |
III | |||||
IV |
P.S. If the matrix has 1 million and one pixel, the defective pixels are rounded up.
For example, for a WXGA class 2 matrix with 1024000 pixels, defects of type 1 - 3, type 2 - 3, type 3 - 6, clusters of type 3 - 3 are allowed.
Values for all class 2 monitors.
monitor types | Pixel defect type 1 | Pixel defect type 2 | Pixel defect type 3 | Number of clusters containing more than 1 type 3 defect |
XGA(1024x768) | ||||
WXGA(1280x800) | ||||
SXGA (1280x1024) | ||||
SXGA+ | ||||
WXGA+ (1440x900) | ||||
UXGA | ||||
WSXGA | ||||
WUXGA |
All of the above does not mean that you will definitely get a display with broken pixels. Often, displays either contain 1-2 defective pixels, or do not contain any at all.
Only in the event that the number of defective pixels of each type on the corresponding TFT display is greater than indicated in each corresponding cell, the product is considered defective and is subject to warranty service.