|"i have tried it with a 550 and 880 w psu, and the same problem each time, i doubt it's a wattage issue..."|
It could be an amperage issue.
Does your PSU have multiple +12v rails of 18-20A each? If it has a single +12v rail, is it over 30A? 20+4-pin main ATX plug? Either a 4-pin or 8-pin ATX12V plug connected to the board? 6-pin PCIe plug connected to the video card (if required)?