Did you try your first boot with as few components as possible? CPU/Heatsink, 1 stick of ram in the B1 slot, 1 VGA in the primary slot (Sli only). Break it down and start from scratch. After breaking it down discharge the motherboard:
Unplug the PSU. Remove components except CPU/Heatsink, remove CMOS battery. Discharge the motherboard by holding in the power button while touching the metal part of the case for approx 30 sec. Put the battery back in, one stick of ram in the B1 slot and 1 VGA in the primary slot and see if you can post. Don't forget to apply your bios settings especially your mem voltage & timing before adding remaining sticks.