Dead pixels look like black dots and don't light up, but sometimes they disappear on their own. Free apps like JScreenFix can try to fix stuck pixels, but they're unlikely to fix dead pixels.

A defective pixel on an LCD screen. Bad pixels are often transistors that are permanently dead and appear as black dots or permanently energized and show up as white or colored dots ("hot pixels").

There are few things more aggravating than a dead or ‘hot’ (permanently lit) pixel on an LCD screen. The trouble is some manufacturers seem to think a few dicky pixels are okay, provided they’re not ...