Video output vanishes and it isn't the video card... suggestions?
I have a high-end dual processor Dell workstation that operated for several years without problem. Recently, the video output has gone flaky, in the sense that after 2-3 days, it loses synch with the monitor (sometimes you can still see a hashed-mess of the what you expect to see on the screen). Poking at the keyboard, and accessing the file system on the machine from over the network, indicates that the machine is running fine and its just the video. A reboot fixes the problem... for another day or two. This in effect makes the machine unusable.