asrock x79 extreme7 wont post after shutdown

[wafer]

my asrock x79 extreme7 wont post after a shut down. for it boot i need to unplug the psu wait and plug it back in for it to boot

the ram, graphics cards and psu came out of my old pc which work flawlessly. my new specs are

asrock x79 extreme7
Intel CORE i7 3930K
corsair h80
16gb corsair vengeance 1600mhz
2x 470gtx sli
2x OCZ Vertex 3 240GB ssd in raid 0
bluray rom
1200w thermaltake toughpower power supply

any way to fix this issue

cheers