A modern LCD or OLED screen contains millions of pixels and yet it can be very irritating if there are defective pixels in between. But are those pixels really ‘dead’ or can you bring them back to life? And what about the warranty?
Arno Beuken
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| It is good to search for the defective pixel |
Most screens of computers, smartphones, tablets and also televisions are TFT screens, which stands for thin film transistor. This means that each pixel, or pixel, on the screen is lit up by several tiny transistors. Each pixel consists of three sub pixels which transmit the colors red, green and blue respectively, the so-called RGB colors. Together, the three ensure that the pixel can produce just about all colors in the rainbow, making the images on your screen or monitor look so color-true. A Full HD screen with its resolution of 1920 x 1080 pixels contains more than two million pixels, an Ultra HD screen already almost 8.3 million. These are awe-inspiring numbers and the technology behind them is therefore fragile. Between all those pixels can be defective copies. A screen or monitor may be damaged during manufacturing or shipping, but pixels may also fail over time.
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| A greatly magnified dead pixel. This is beyond repair |
DEAD, CLEAR OR FIXED?
You often hear the term ‘dead pixels’ in this context. That term doesn’t quite cover it, ‘defective pixels’ is a better description. There is a big difference between ‘dead’, ‘bright’ and ‘fixed’ pixels. Not only in meaning, but also in terms of whether they can be remedied or not.
A pixel is ‘dead’ if it no longer transmits any light at all. The result is a black pixel, which you can especially recognize on a white or light background. This dark point is unfortunately not recoverable, over and out. ‘Bright’ pixels are the opposite: pixels in which all three sub-pixels transmit light constantly. Red, green and blue in the same intensity produce the color white (apart from the question of whether white is a ‘color’). Such a bright or ‘bright‘ pixel you see on a dark background as a white dot. With a ‘fixed’ or ‘stuckFinally, the transistor of one of the three sub-pixels has jammed and the pixel only lets the light of that one RGB color through. With those last two phenomena – bright and fixed pixels – there may be something that can be done about it.
RECOGNIZE AND RECOVER DEFECTIVE PIXELS
There are all kinds of websites that check whether your monitor or screen contains defective pixels. A Dutch example is Dodepixels.nl/test
The test on this site makes your screen alternately completely white, black, red, green and blue and against those backgrounds you can detect any defective pixels.
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Dead Pixel Buddy (filecroco.com/download-dead-pixel-buddy) is a freeware Windows program, in which you can choose and fix the colors yourself, allowing you to inspect your screen longer. Chrome has an extension that does the same thing, and for Android devices, there’s the Dead Pixels Test and Fix app, which can be found on Google Play.
There are also free sites and programs that claim to fix bright and solid pixels by reactivating them. They do this by bombarding the pixel’s surroundings with a field of alternating colors, which in fact looks like colored noise. An example is JScreenfix (jscreenfix.com). when you do this portable program (so without installation) and you drag the noise field over your defective pixels, this may bring them back to life. JScreenfix promises a 60 percent success rate. Another example is PixelHealer (aurelitec.com/pixelhealer/windows/download), which is also available in a portable version.
There is a video on YouTube that does the same: youtube.com/watch?v=ZjdrMuKpaCI We found this last reference at Coolblue, in response to a customer with a complaint about a television with defective pixels. People who suffer from epilepsy are strongly advised not to look at these kinds of bright and flashing images!
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Jscreenfix: drag the field over a defective pixel |
DO YOU HAVE WARRANTY?
We said it before: TFT screens contain millions of pixels. So how disturbing is it when a few of those pixels fail? In the first place, that is of course up to you: how critical are you? Chances are you won’t even notice a single dead pixel. But if you are a sharp viewer or, for example, a graphic or web designer, it can be terribly disturbing. And several defective pixels together quickly form a defective ‘lump’. Moreover: you pay a lot of money for that computer, monitor, TV, tablet or telephone, partly because of that beautiful screen… Then it just has to be good, without defects?
However, defective pixels do not simply fall under the normal warranty scheme. Suppliers and shops state that a dead pixel is not a technical defect, but a ‘cosmetic imperfection’ that they cannot do much about themselves. You can only claim under warranty if your screen has several defective pixels. Most screens and monitors fall under class 2 of the ISO standard specified for this (ISO 13406-2). It says that per million pixels there may be two ‘dead’, two ‘bright’ or five ‘solid’. You can calculate for yourself how that relates to the resolution of your screen. Only above these numbers you have the right to speak at the store.
TO ENSURE?
To fully cover the risk and because defective pixels can also develop over time, some sellers offer a special pixel guarantee or insurance. A random selection: at Megekko this insurance costs € 49.95 for a period of three months. With Alternate you pay the same amount, but for six months and only for monitors with a value up to € 499. At Azerty you can buy a 30-day exchange guarantee for € 75, but only for individual monitors from € 801 to € 1000. So check carefully what the policy of your favorite store is. Finally: if you buy an expensive (TV) screen at a large retail chain, you can often take out extra damage insurance. In that case, ask explicitly whether defective pixels are also included. Usually not, because, as mentioned before, they are not seen as a technical defect.