I have a machine whose video keeps blinking out after 4- 5 minutes. The CPU is still running, and the monitro is on, displaying it's "no signal" screen. When i reboot, it comes back up, but then blinks out again. I've replaced the video card, which fixed it for about a month, but now it's back. This doesn't seem like a monitor issue, but I suppose it could be. Could it perhaps be an overheating issue with the MB? A memory issue? I replace the power supply on this machine not too long ago in response to total blackouts. Any ideas would be appreciated.