LCD Screen burns are caused by leaving a fixed image on a screen for too long, which causes a "ghost" of that shape, design or color on that part of the screen that persists, obscuring other images. The damage is usually not so bad as to make it impossible to watch anything, but significant enough to impede the watching experience--particularly if it obscures some important piece of information like the score of a game.
Repair Steps
Hook up a standard computer to your LCD TV screen. Instructions for how to do this should be included with your TV. If you have lost the instructions, the manufacturer should have a copy of the manual available.
Create a blank white image in the image editing program of your choice.
Set the image as the screen saver for the computer. Activate the screen saver. Increase your TV's brightness to the maximum level. Leave it on for as long as the image burn remains, then unplug the computer and continue running the TV as usual.
Some Tips
Maintain the TV properly to avoid burn problems in the future. Leaving the TV on for extended periods of time on fixed images will damage the screen. Changing the channel occasionally when watching a program that has a persistent, unmoving image in a certain area--such as a scrolling newsbar or a graphic displaying the outdoor temperature and current time--can prevent burn issues. Turn the TV off when it is not in use to prevent burns and dead pixels from developing.