Gateway fpd2485w lcd shows video then cuts off

Hi I have a Gateway fpd2485w that powers on shows gateway logo then the video cuts off. Every time I unplug the video cable from the monitor and plug it back in it shows video for a second and then cuts off. It appears that it won't hold a signal. Please help. Exact same thing happened here this morning. I cannot get video back no matter what I try. Grrrrrrr. Unplugged for 30 min then tried again. Tried 2 different computers. Tried DVI and VGA. Tried through KVM and direct. Tried different resolutions and color depth. Nothing helps.