I only said to use the screwdriver to elminate the case as the problem. There are two pins on the motherboard that control the power right? Just use a screwdriver and short the two pins, it mimics the power button, since thats how it works. (I only said that since the case might be broken). Look for little stuff, is everything plugged in right? Also try reseating EVERYTHING, something may have come loose when you put in your new sound card. Why not try removing the new x-fi and seeing if it starts then? Try a different PCI slot?