i had that prob before, leaving a hd magnet on my desk once. i put the monitor on its front for the night, and when i woke up, and re hooked it up, it worked right again. matter afact, im writing to you thru that monitor right now...lol, hope it helps,(o and peeps, deguass works for having two monitros side my side taht get the flicker, if u got dual monitors u no wat i mean)