i have 1 stick of 2g ram which was a mistake was ment to get 2 sticks of 1gig. WhoopsIt may not be the graphics card at all.
How many sticks of ram do you have? If its more than 1, try removing all, then stick in 1 in slot 1.
Unplug all the ide and sata devices to.
Once something appears on the screen (if it does) you can add stuff in until it misbehaves again.
Is there a connector on the motherboard for extra power, mine has a molex plug near the cpu, to provide extra juice for these new power hungry chips.