I have came across this graphic problem on my laptop for about a month. While working the screen start to blur with an appearance of ascii characters on the screen then thin silver vertical lines appear across the screen and then screen crashes to blue screen that later turns white and computer resets itself.
On restart 5 pairs of multiple rgb vertical lines appear on the screen. The system crash if I start the windows normally. While the system works fine with other modes like command; safe and safe with networking. But I still see those vertical lines. They are spaced apart about like several inches. So I can see the words and images between the RBG lines. These lines also appear when I try to connecting the external display.
After a few days time it start to work normally and the lines disappeared. It has been working fine for the past few days and then problem started again. This time I got the amd crash messages. It has stopped working and now recovered. I also noticed the lines appearing then the message and it worked fine and few moment later those RGB lines returned.
My system specs are as under
Os Win 7 premium
Dell XPS 1640
i7 1.79 GHZ
8 GB ram
320 GB hard drive
1 GB ATI HD 4670.
I have also noticed that running dell diagnostics before the start up by pressing fn and F3 with the battery icon and removing the battery pack and starting with direct power cord. This took some time and settle the issue. Now it does not seem to be working. Sometimes running windows in the safe mode with networking seems to settle the problem. I have already cleaned the fan off the dust. I also could not differentiate here whether it seems to be due to hardware or software problem. I also tried re-installing the latest ATI catalyst driver but with no luck since my computer crash normally and I cannot run setup in the safe mode neither do online dell diagnostics. When my pc was working fine in between the spells of RGB lines the diagnostics did not pickup any problem.