LCD screens are made up of a fixed number of pixels. Each pixel is made from 3 sub-pixels: 1 red, 1 blue and 1 green. Each sub pixel has its own transistor, so we can find that the manufacturing process to produce a TFT LCD panel is highly complicated. Due to the complex process, defects can occur at any time during the life of the TFT panel---- Occasionally,  those individual transistors on LCD display will short or remain open resulting in a DEAD PIXEL. These defects cannot be fixed or replaced.