BleepingComputer.com: screen blinking / blacking out

Hello all.
A while ago I foolishly allowed a suspect email to install a virus on my system.
It pased AVG checks several times, (at each unpack zip stage) and I eventually got rid of it, I thought.
I was unable to restore to a previous saved restore point as each time it failed on reboot.
I was left with a system that would "blink".
It starts as though you are changing resolutions. A quick off and on.
After a while, (and normally once I have a few Firefox windows open) it gets so frequent that it is only briefly blinking on. You can normally restore a picture by moving the pointer to the bottom right over the task bar which says display desktop but as soon as you move the pointer away the screen goes black again.
Occasionally I can close on of the Firefox tabs and all is well for a few minutes.
It does this occasionally on the logon screen.
It does it when Firefox is open.
It does it when Firefox isn't open.
It has started to be completely black on the startup screen but not every time.
I have tried:

Reloading Windows 7 Professional onto a fresh drive. A 160gb SSD. Same results.
Changing my Graphics card from a Gainward GTX570 to an Xfx 5870. Same results.
It happens when the machine is cold and when it is warm.
Resource monitor shows no Memory spikes.
I have virus checked, Malware checked, registry checked etc.


Please can someone help me?
I have several 023 file missing / user unknown listings from a Hijack this scan but have no idea what any of it means.


Just to Add. I can start the system in Safe mode with network and it all works fine.
Totally confused!!!!

This post has been edited by thepurser: 03 November 2011 - 06:11 PM

Ports, broken pin, cable or power supply. Also check the monitor on another PC. You could also try the Am I Infected section.