Hi I have a desktop machine based on an Asus M5A78L with an Athlon X2 260 and a Radeon HD4730 video card.. It ran Fedora16 and Wn7 from two separate drives and until recently worked without problem. Then it started requiring two goes with the password to get Fedora to boot.Windows still seemed ok. It then got worse and started producing white flashes as the mouse moved around the screen., but still looked ok when the application screen appeared.. It then started putting multiple white lines across the screen, a bit like music staves and also miss-reading some letters in text.
Finally it stopped part way through the linux boot and said "Oh Dear there seems to be a problem", Windows still ok. I had a spare new drive so I installed Fedora 20-64 on this and it seems to be working most of the time but I still get periods where odd artifacts appear on the screen, some of which appear even before the motherboard Splash screen appears.
These take the form of two or three groups of twizzling vertical blue lines. Even when this occurs Windows seems to clear it and works normally. This was written on the machine in question! Where should I look?