When you buy an LCD TV, you may get a copy with dead pixels on the screen. Returning such a TV to the store will not be easy. Therefore, it is important to know how to check your TV for dead pixels before purchasing.
A pixel is a cell involved in forming an image on a screen. The main pixel consists of three subpixels: green, red and blue. By combining these colors, you can achieve different shades and colors.
When the matrix is in good working order, the picture on the screen is free from defects. If any pixel or transistor that controls it is damaged, a defect appears, which is called a "broken pixel".
Broken pixels are non-burning and burning. A non-burning pixel appears as a black point. A lit pixel glows white continuously. They appear against a contrasting background. Another defect is a broken or "stuck" subpixel. It manifests itself by glowing in one of the primary colors - blue, green or red.
Why check the TV for dead pixels
The presence of dead pixels does not affect the overall performance of the TV. Most manufacturers allow a certain amount of defective pixels on the screen. This amount depends on the monitor class and is usually indicated in the warranty documentation.
If you do not check the LCD TV when buying and only at home to find the presence of dead pixels, it will be very difficult to return such a device to the store. If their number does not exceed the norms established by the manufacturer, the TV will not be accepted in the service center either.
The manufacturer does not consider this to be a malfunction or breakdown. And in most cases, the restoration of dead pixels is impossible. Therefore, check the TV directly in the store, where you can refuse to purchase if you find a defect.
How to find dead pixels
Checking for dead pixels is pretty straightforward. Since faulty pixels have a consistent color, they show up well against a contrasting background. You will need to display several color fills in succession.
How to do it? It is advisable to connect the TV to a computer or laptop. This will allow you to use special programs to test monitors and televisions. In addition to checking for dead pixels, these programs will allow you to check a number of other important parameters. The most popular program for this purpose is TFTTest.
Not all shops will meet you halfway and provide you with a computer. You can of course bring your own laptop. But if the TV model you have chosen is equipped with a USB interface, it is enough to take a USB flash drive with you. Record a video on it with a sequential change of the desired colors or just images with fillings of different colors.
Connect the drive to your TV and start a video or image viewer. As different colors are reproduced sequentially, carefully examine the entire screen area. Broken pixels, if any, will show themselves as contrasting dots.
