I just got a leadtek GF4600ti and I put it in my machine and when I turn it on the machine goes on for one sec and goes off completely. I put it in my back up rig and it works fine so its not the card. I also took out my Antec 400w and swapped it for a the back up rigs psu and it does the same thing. This leads me to believe it the Mobo. My Radeon is fine in the machine so I checked the bios and all is well, but when I put the 4600 in it, it doesn't run for more than a second. PLEASE HELP, the rig is in my sig.