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Dead Pixels on Notebook Screens
"LCD screens are generally the most expensive part of a laptop
computer. They're also the most likely part to contain noticeable
flaws in the form of the dreaded dead pixels. Each notebook
manufacturer has their own policy on how many dead pixels warrants a
return and replacement. The problem is, most people are not aware of
this policy before they get their notebook and falsely assume that one
dead pixel is good enough to ask for a replacement, but this is
generally not the case."
"So What Causes a Dead Pixel?
Occasionally the individual transistors responsible for carrying
current to a pixel will either short out or remain open resulting in
what is called a dead pixel. A "lit" pixel is one that appears as one
of several randomly placed white, red, blue or green pixel elements on
a dark background, or you may have a "missing" pixel which shows up as
a black dot on a light colored background.
So Why do New Screens Have Dead Pixels?
During the production process of LCD screens it is difficult for
manufacturers to assess if a pixel is out or not. In fact, only once
an LCD panel has completed production and assembly can it be
determined that an LCD does or does not have dead pixels. Material
costs are high for LCD displays so every attempt is made to avoid
scrapping displays. If a screen is determined as being overly flawed,
it will be thrown out, but if the screen is within a set quality
standard -- say 2 dead pixels -- then the screen will not be thrown
out. If manufacturers had to throw out every screen with even 1 dead
pixel, prices would be much higher for LCD screens."
"Are bad pixel only a problem on new LCDs or can a pixel become bad
over time. I mean, is the transistor failure due to production or does
failure often (or less often) occur after the LCD is in use."
"Dead Pixels can occur over time."
Dead Pixel Test
"If you notice dead pixels, sometimes you can massage them back to
life: just rub the screen by pressing a finger gently through a rag
around the pixel. No guaranty but sometimes it works; LCD monitors are
fairly fragile, so take it easy."
LCD dead pixel cause