If it is the PSU's fault i might replace it with the 'Corsair VS650', any thoughts on it, is it good enough for the build. I will be using the computer for gaming a lot.
At this point, I would tend to suspect the PSU, however it could be the graphics card itself. You could RMA the card, and if it still wouldn't work, then replacing the PSU would be in order. The Corsair PSU would be a good one for a single graphics card. If you anticipate going crossfire in the future, I would bump up the wattage to 700-750, just to have some headroom.