Defective Pixel
Defective Pixels are pixels that aren't performing as expected.
There are several kind of defective pixels, but in this blog, we'll go further with the dead and stuck pixels.

In a dead pixel, all three sub-pixels are permanently off. Dead pixels can result from similar manufacturing anomalies as stuck pixels, but may also occur from a non-functioning transistor resulting in complete lack of power to the pixel.
Dead pixels are much less likely to correct themselves over time or be repaired through any of several popular methods
Stuck pixels, unlike dead pixels, have been reported by LCD screen owners to disappear, and there are several popular methods purported to fix them :
  • Gently rubbing the screen (in an attempt to reset the pixel). Please perform this action with the help of microfiber cloth.
  • Cycling the color value of the stuck pixel rapidly (in other words, flashing bright colors on the screen). You can use Dead Pixel Tester Software to do this.
  • Simply tolerating the stuck pixel until it disappears (which can take anywhere from a day to years). 
While these methods can work on some stuck pixels others cannot be fixed by the above methods. Also, some stuck pixels will reappear after being fixed if the screen is left off for several hours.

 Sample of a dead green sub-pixel


Please visit SOFTPEDIA if you want to download DEAD PIXEL TESTER Software for your monitor or you can GOOGLE to find others.

Please visit WIKIPEDIA  if you want to read further about DEFECTIVE PIXEL.
Or you can GOOGLE  to find other articles about it.