have you:
1) connected pcie power to the graphics card, if so are these pcie power connectors or are you using molex to pcie converters?
2) if using molex to pcie converters you may be drawing too much power away from the hdd, thus failure to boot/properly init drive will hang system
3) is there a bios mode switch on the graphics card? if so toggle it and see if it helps.
4) stick your head near pc with side off when booting, with card in, check fans on card are spinning up, listen for the hdd spinning up, disconnect any auxillery components such as optical drives and molex powered fans.
5) remove all sticks of ram, inset just one, try booting, go through each stick one at a time to eradicate the potential of bad ram
6) get a new PSU with enough pcie cables to feed the gpu, you dont need to go nuts with it, 650W one would be fine for you, if its 80 gold rated then you'll sit right in the highest efficiency bracket with that hardware anyway.







