In this article I will explain what a pixel is and for what reasons it can get stuck. I will then show you how you can identify bad pixels on your LCD screen and what you can do to possibly fix them yourself. Only after you have tried all your options, is it time to claim your warranty.
What Are Pixels?
Simply put, pixels are single dots in a raster image and all of them put together make up the entire image.
What you are seeing on your computer screen right now, technically, is a raster image made up of hundreds of pixels. On CRT, LCD, LED, or plasma displays, however, pixels are not static, they display moving and ever changing images, therefore they must change colors. To achieve this, every pixel is divided into three sub-pixels, i.e. red, green, and blue. Each sub-pixel is powered by a transistor that controls the on/off state of the pixel.
What Is A Bad Pixel?
A bad pixel is a pixel that does not display the color you expect it to display. It is either stuck in a certain color, temporarily off, or permanently off, which equals a dead pixel.
Generally, what can happen is that the liquid crystal inside a sub-pixel is not evenly distributed, therefore that pixel never lights up. If all three pixels are affected, you get a pixel that is temporarily off. Another scenario is that a transistor is broken and consequently the pixel is permanently off (dead) or possibly also permanently on (burning). The latter is the worst case scenario as you cannot fix a broken transistor. You may, however, be able to fix problems with the liquid crystal.
How Can I Find Out Whether Or Not I Have Bad Pixels?
There are several online tools and applications you can run on your computer to identify bad pixels.
I have previously recommended the online LCD test tool from Flexcode. Since then, they have provided an updated version of the tool, which comes with a much better interface, making it easier to use. Simply run all five color tests (green, blue, red, white, and black) one after the other and check your screen for irregularities.
Like the previous version, this one also includes a ‘massage the pixel‘ option, which may possibly fix a stuck pixel by over-stimulating it. So should you spot bad pixels or find darker regions on your LCD screen, run the ‘Fix My Screen‘ mode for a longer period of time (about one hour) to revive the affected pixel/s.
IsMyLcdOK is a portable application for Windows. You can easily zap through the various test screens using number keys, as well as F2 through F5. F1 brings up the options overview.
Mac users may want to try Pixel Fix, a Dashboard widget to cure stuck pixels on LCD screens.
I Found a Bad Pixel – How Can I Fix It?
The only way to fix a stuck pixel is to over-stimulate it and pray that it comes to life again. You can over-stimulate pixels in two different ways – you can either send rapidly changing signals to the respective pixel or you can manually apply pressure to the respective area on your screen.
I have described both methods in my previous article 5 Ways To Fix A Stuck Pixel On Your Screen. Briefly, you can use the ‘Fix My Screen‘ option of LCD2 (see above) to treat the entire screen. If you can’t have your whole screen blocked for up to an hour, you can also use the ‘undead pixel’ option of UDPixel (screenshot below), to locally fix a bad pixel. Finally, the most successful method appears to be the manual one, i.e. applying pressure to the area of your screen that has the dead pixel.
For a thorough description, please refer to my previous article.
If none of the methods worked instantly, try again and try several times. As you can see from the comments to the first article, it is very possible to fix bad pixels!
For more information about LCD monitors and a huge selection of test images, check out The Lagom LCD monitor test pages.
Have you ever succeeded in fixing a stuck pixel and how did you do it?