I'm having real problems with my pc.It started a few weeks ago after it started acting really strange, by shuting off etc.At first i thought it was the CMOS battery, which i replaced.The same problems have started again, so it's not that.After being online for maybe half an hour or so, the screen starts to dim very slightly, then lighten to normal resolution.After this happens, the screen will just shut off totally.I then have to turn the pc off at the power button, and then reboot.The strange thing is that i thought at first this was the monitor for obvious reasons, but sometimes when i reboot, i get the black screen telling me there was an unknown error, and to resume from the last best known configuration.Also when i start up the pc after a day or so, there is a dark band of lines that are in deep black covering the first 5 inches of the screen from the top.This black band only shoes clearly when the screen has a white background.I'm really at a loss as to what could be causing this.Any help would be greatly appreciated.I'm running Windows XP.Thanks.
Try reseating the graphics card-assuming its not an onboard one. (if its a pci type, try it in another slot) also, next time it happens, try wiggling the plug where it goes into the computer (from the monitor) and also at the monitor end if there is a plug there as well. You might want to think about a can of switch cleaner for these. Do NOT be tempted to try using some kind of oil type spray like wd40, and if you do, please do it with the machine switched off.