Dead Pixels: black, white or colorful?
When we talk about Dead Pixels, we do not mean the mildly popular British sitcom about three friends fixated on a fictitious online role-playing game. We mean pixel dots on screen of an LCD that are not working properly: failing to reproduce the correct light levels.
Let’s start with the basics. On a standard TFT display one pixel consists of three sub-pixels: red, green, and blue. When for some reason one of those sub-pixels is stuck in the wrong position it starts blocking the light from passing through that layer. A small dark dot appears on the screen – that’s the bad pixel (or dead pixel). However, when the entire pixel is stuck in the wrong position opposing to the one above, then all light can pass through that layer and it creates a white, bright pixel on screen. This we call a bright pixel (or lit bad pixel). There are several types of that bright pixel. You might see little pixel dots on screen, that are either red, green, or blue. It depends on which sub-pixel happens to be stuck permanently, letting the light through. While there are more scenarios where a pixel can be faulty and become bright pixel, these three summarize the most common situations pretty well.