I have 2 x 5870. Today i started my computer and one of the cards started with the fan at max speed with a loud noise. In windows crossfire did not work and it the card was not detected . I took the cards out and i left in the computer only the one with the problem, change the slot and the computer started. then i put the other card in and it worked. I started after some time the computer again and now it will not show anything on the screen because the card with the noise it's connected to the screen. Whan can be the problem? Is that card dieing?