One of the most common problems with a computer monitor is the appearance of individual dots on the screen, the color of which does not match the picture. The reason for this is the damage or malfunction of the screen matrix, the minimum size of which is considered to be a pixel. This term refers to an indivisible rectangular or round object with which an image is formed.
Several types of problems
Such a defect as dead pixel may look different:
- elements that always remain off are called “dead pixels” and will look like dark dots on a light background;
- pixels that always work are considered “hot” – you can see them on a dark or completely black background, where they continue to remain white;
- “Stuck” refers to elements that do not change color – they become noticeable only when the shade does not match the main image.
Important: if several pixels in the same area fail at once, this damage is called a “group of dead pixels”. Together they are folded into rectangles ranging in size from 2 x 2 to 10 x 10 elements, or even in a horizontal or vertical line.
Permissible number of dead pixels
Check the monitor for damaged matrix elements immediately upon purchase. Such a check will avoid problems with returning the product under warranty and conducting an examination proving that the cause of the malfunction was a factory defect and not the user’s actions.
In accordance with the ISO13406-2 standard, a certain number of defective elements is allowed for each monitor. Therefore, even if checking the monitor for broken pixels showed their presence, this will be considered normal in such situations:
- the product belongs to the 4th quality class and can have up to 50 “hot” pixels, up to 150 “dead” and up to 500 with other types of defects;
- the matrix is released in class 3, which allows for the presence of up to 5 constantly on, up to 15 elements that are not working all the time, as well as up to 50 pixels with other problems;
- the monitor’s quality class is second, and up to 2 “hot” and “dead” pixels and up to 5 “stuck” can appear on the screen;
- the first class of the monitor – there should be no dead pixels at all.
You can count on the complete absence of defective elements only when purchasing first-class goods. However, most serial models relate to the second, and when they are checked, you can find 1-2 or even 5 incorrectly working pixels. Although the monitor class shows how many defects are not considered defective, in fact, most products do not have them completely.
It is recommended to determine the presence of matrix damage in the store where you buy a monitor. However, if this is not possible or the product is purchased online, the check can be carried out at home. To do this, use an online test or a special program, although noticeable defects can be detected with the naked eye.
Visual check method
The simplest test of a monitor for broken pixels is to display a plain background of standard colors – black, white, red, green and blue. These five options allow you to detect “burning”, “dead” and “stuck” pixels.
You can check the monitor for defects in this way both at home and in stores. In the latter case, the backgrounds are copied to the USB flash drive and run on the computer connected to the purchase. In addition to monophonic images, you can use test images by finding them on the Internet.
Another way to find defects is a program for checking the monitor for dead pixels. You can use the appropriate application both at home and in the store, having recorded not test images on the USB flash drive, but one of the verification utilities.
Dead pixel tester
One of the most popular monitor testing software is Dead Pixel Tester. You can download it from the official site.
To check, you must perform the following actions:
- Launch an application that does not require installation, and select the appropriate mode in the Pettern section and color using the Color Selector button.
- If necessary, set the mode change using the Auto Color Cycle option.
- Check if dots that do not match the color of the picture appear on the screen.
The Exerciser function, activated by pressing the corresponding button, allows you to find defects in a specific part of the screen. It creates a rectangular area that you can drag around the screen in search of dead pixels.
Another program suitable for diagnosing computer monitor matrices is IsMyLcdOk. It can also be downloaded for free and does not need to be installed. Instructions for performing the verification appear on the screen after the first start.
The test is started with 4 keys – from F2 to F5. In the list of available test modes, there is an output on the screen of colored stripes, rectangles, vertical or horizontal lines. In addition to standard tests, you can display a plain or gradient picture.
Online Services for Verification
If you can’t download and run the utility (for example, due to restrictions on downloading and running on a working PC), you can check the monitor for dead pixels online. There are a lot of sites that allow you to find defects, but among them, there are two of the simplest and most convenient to use.
Repair Damaged Areas
- Sometimes the functionality of a damaged matrix can be restored without contacting the service. You can decide how to remove dead pixels on the monitor after you understand where they came from. If the control transistor fails, remove the damaged screen element only with the help of a special laser. However, if the cause is a subpixel freeze, the user can get rid of the defect by using the Bad Crystal program.
- The UndeadPixel utility also performs very well. If you find a pixel error, launch the application by clicking “Start” in the “Undead Pixel” section. A square will appear on the screen that changes colors. Using the Drag & Drop function, you can move the square over the defective area. A constant color change should occur within a few hours – after such a procedure, the pixel can be restored. Note that bring back to life all black pixels already impossible.
- The free program EIZO Test Monitor (suitable for any device) contains 24 test images and helps you quickly optimize color settings, as well as check the screen for dead pixels. This utility does not require installation. Unzip the ZIP archive and run the application with a double click. After that, click on the “Start TEST” button. Eight scenarios are available in the utility, including calibration of brightness and contrast. If you need to change any settings, the program will tell you how to do it.
- Another treatment option involves physical exposure. To remove the damage, take a cotton swab and gently press on the broken pixel. In a few minutes (from 10 to 15), a failed element can earn. It will be possible to cure the matrix in this way if the pixels were “stuck” or “hot”.
Features of returning the monitor to the store
If all else fails, the user who has discovered the defect has the right to return the monitor or exchange it for an equivalent product. Within 14 days, a refund is made without indicating a reason: it is enough to provide a sales receipt or cash register receipt and packaging of the returned equipment, on which there should be no traces of use.
If 2 weeks have already passed since the purchase, the buyer has the right to rely on the warranty repair of the monitor or its return if the device cannot be repaired. However, in this situation, the equipment is first sent for examination: according to its results, it is determined at whose expense the monitor will be repaired – the buyer or seller.