firstly, find & press the 'reset' button. then setup monitor display as usual.
if that doesnt help, proceed with next point at your own risk & discretion
google the web for either
a) service manual
b) service menu (how to access the service menu on your TFT)
the service menu is hidden and usually requires a 'hot key' combination.
once accessed, there may be 'auto scan' settings, contrast, colour settings.
you may be able to tweek a few. but please, proceed with caution & note every setting you alter & do it in increments. (at your own risk)
traditional CRT 'burn-in' isnt possible on an LCD. CRT screen-burn happens because the phosphors get embedded with the 'light energy' (image) after extended period of time. at bit like photographic paper or your retina when staring at a light source.
LCD's do not have phosphures.
it sounds like you (may) have stuck pixels on a particular colour range.
download this & test your monitor
it has loads of features, but real simple point & click tests. great for testing out monitors before purchase & dead pixels.
go through the tests, red, blue, green, greyscale etc & see if the image dissapears on certain colour washes. this may identify if you screen has stuck pixels on a specific colour range, or electronics arent 'refreshing' correctly.
sorry i cannot provide definitive remedy
let us know how you get on
Most likely you've got a electronics fault.
something isnt refreshing correctly. The annoying thing is it will (most likely) be a 25p resister, capacitor or triac etc.
If it was me, i'd have a close look at the pins on your cable. would a break in one of the miniature cables cause this due to lack of signal no reaching the TFT? if you are able to swop the VGA/DVI cable or borrow one, who knows?
it just seems odd the way the pixels have 'stuck' with an image.
tiger123, i'm fresh out of ideas now.