Ok, so i have just reseated and re-applied my thermal paste, so i switch pc on and nothing appears on the screen. Judging by the short beep as well as the keyboard lights coming on and flashing regularly im assuming there is a problem with the video card or something. But i took the power cables out and put the back in and gently pushed the card in and it was firm. The monitor comes up with a message that says analog then digital and back and forth between those. So what could the problem be?