Hi, Today I use my computer as usual, but after using for a while (usually an hour later) , 2 vertial lines appear on screen and I have to restart or press sleep to remove those annoying lines and it appears 3-4 times up to now. Can anyone tell what's happening to my computer? Is it a video card problem? I am using ATI Radeon 9800 Pro, and my monitor is ViewSonic E70. Thanks.

I'm guessing that you haven't spent the day word processing. With the setup you have, I'm thinking games. As this occurs after an hour, it is likely to be heat related. The video card is the only likely suspect. Check that the heatsink isn't clogged with dust. How many case fans are you running?

Thanks for your reply! I did play games few months ago. But now I rarely play games, I mainly use my computer on surfing the internet. I have totally 3 fans - 2 case fans and one additonal from the power. Actually I did a dust cleaning on my computer this morning, and the problem's found just after I cleaned the dust and boot up my computer. The first time is my worst experience that the screen showed 2 vertical lines just 2 minutes after I booted up my computer. And I rebooted my comp, but the lines still existed. Finally, I shutdown my computer and booted it after 15 minutes, the vertical lines gone. After that, the lines appear every 45 minutes- 2 hours and I must press sleep to remove them.

0. Are the lines there in the BIOS or only visible within windows? I would suggest physically reseating the video card. -- Have a Happy Holiday --

For the first time the lines appears in 2 minutes after computer boots up. It's in bios and in windows Then the lines only appear in windows and only appears after an hour or longer. ok I will try to reseat my Video Card Thanks !

no fan on video card & is it a seperate card or built in. if a card try an agp slot fan beside video. also try another monitor to see if problem stays or goes away david

My Radeon Card has a small fan on the card I will try your suggestion Thanks a lot!