I have a networked HP computer with XP Pro, service pack 3 with a Samsung Syncmaster 920nw monitor.
As soon as the computer is turned on the monitor comes on for about a second, then goes black. If you turn the monitor off, then back on again it works again for about a second before going to black again.
The power light stays solid blue (if the computer goes to sleep or is turned off it blinks.) It logs into Windows fine, even though it's a pain to do even that because you have to shut the monitor off & turn it back on repeatedly to do anything, and gives no error messages or anything like that. Power-saver is set to never turn monitor off or go to sleep (that seemed to work for a few hours yesterday even though it doesn't seem to be the problem since it's going off after mere seconds instead of minutes or hours, but today it's not working again.)
Any ideas what might be causing it?