Stuck pixel

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A stuck pixel is a common pixel defect on LCD screens, where any number of the 3 sub-pixels are faulty, producing (most commonly) permanent red, green and blue pixels on the screen. Similar to (and often falsely labeled as) a dead pixel, whose 3 sub-pixels are permanently off, producing a black pixel. While one is not very noticeable on a high definition screen, stuck pixels tend to occur in groups, and are most easily noticed on dark or black screens.

Like dead pixels, stuck pixels have become an issue for owners of the PlayStation Portable, as many PSP displays contain at least one defective pixel (in rare cases screens can contain 10 or 20 stuck pixels).

The definition of a dead pixel is one that won't respond to commands. In the case of transmissive displays like PC monitors, a dead pixel is actually one that lets light through. A PC monitor will rest its pixels in the 'let light through' state (this can be observed as the washing out effect witnessed on a LCD panel when the power is pulled or unit enters stand by).

A stuck pixel is one that remains in the 'block light' position. That is, the pixel thinks it is being powered to 'darken' that particular element. It requires less power for a LCD display to let light out (white page - or backlights and a disconnected display panel) than to stop it (black image).

Fixing stuck pixels

Unlike dead pixels, stuck pixels have been reported to disappear, and there are certain methods to fix them, such as gently rubbing the screen (in an attempt to reseat the pixel), flashing bright colors on the screen, or simply tolerating the stuck pixel until it disappears (which can take anywhere from a day to years), although sometimes stuck pixels will remain on screens permanently.

The "flashing of colors" method has recently gained public interest after a video that quickly flashes the main RGB colors have been produced to help in fixing stuck pixels in the PlayStation Portable. This video is said to be inspired by a DVD that some TFT TV retailers distribute to their customers who report stuck pixels. A portable Java application using the same concept has also been created for PCs, and a homebrew application for the Nintendo GameBoy Advance is available for owners of GBA SP and Nintendo DS systems. Although this method gives no guarantee of success, a rate of up to 60% has been reported by users who left their screen flashing overnight.

It is strongly recommended to run the program with the system's screen covered to prevent someone with photosensitive epilepsy from being affected.

External links

[Understanding LCD monitor defects and policies]
[Color flashing video for fixing PSP stuck pixels]
[Color flashing homebrew program for fixing GBA or Nintendo DS stuck pixels]
[Color flashing Java application for fixing PC TFT stuck pixels]
[UDPixel] - another application for fixing stuck pixels. Windows only - requires .NET. Available in French and English versions

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