the problem cannot be due to moisture.. as he says it works fine on his onboard card.....
plz check that the drivers of card are properly installed and windows recognises your monitor > check this control panel > system > device manager . remove any conflicting drivers of your monitor or reinstall them..
before this this trick is worth trying.......
there should be OSD button on your monitor... access it and check the RGB setting and play around with them and do remember them before setting them so that you can revert back if something goes wrong.....
more over check that degauss is on from > OSD > SPECIAL . this should solve your problems....