how many watts is the power supply?
what kind of video card is it?
both are key parts. If the video card is failing(which it sounds like the problem), could be due to not getting enough power from the power supply.
My girlfriend's monitor freezes and shuts down by itself within an hour of booting the computer. This continued even after we replaced the monitor. I say it's her video card but she insists it could be the power supply. She had the power supply changed like a year ago, so she suspects the new one is defective too. Folks, help before this monitor issue freezes our love too. The compuetr is HP 510n, Celeron, with a 512mb Ram (out of the box it had 128mb)