A dead pixel is a defective pixel that remains unlit, permanently lit, or a solid color on an LCD screen or monitor.

In LCD manufacture, it is common for a display to be manufactured that has a number of sub-pixel defects (each pixel is composed of three primary-coloured sub-pixels). The number of faulty pixels tolerated before a screen is rejected is dependent on the "Class" which the manufacturer has given the display (although officially described by the ISO 13406-2 standard, not all manufacturers interpret this the same way, or follow it at all). Some manufacturers have a zero-tolerance policy with regard to LCD screens, rejecting all units founds to have any number of sub-pixel or pixel defects, meaning the display is a "Class I" display. Others reject them according the number of total defects, or the number of defects in a given group, or other definitions.

In some cases, the manufacturer sends all screens to sale, and then replaces the screen if the customer reports the unit as faulty and the dead pixels meet their minimum requirements for return.

Recently, this has become a hot button topic with the Sony Playstation Portable system as many units have shipped to sale with dead pixels to varying degrees, and there has not been a clear policy on return requirements.

External Links

Tom's Hardware Guide investigates dead pixel policies