when you say "dead," do you mean "bright?" i.e. you have a red/green/blue sub-pixel always on? if so, you can't fix it. An LCD sub-pixel is actually "on" or bright when it is not powered; powering the ...
A pixel on your computer monitor or TV screen may be a very small thing. But if it is not acting in perfect concert with all the other pixels in the screen, the malfunction will stick out like a sore ...