Hey I have a weird problem. I have two gtx 680 cards installed in my PC and I noticed when I shut down my PC the fans on the cards don't turn off. Off or sleep they keep spinning. They do slow down but not off I can see them spin a little. The only way to turn them off is by turning off all power to the PC from the psu switch. Any ideas. Could the cards be dying ??? Btw they are Msi gtx 680 twin frozr. Thanks