Installed the ASUS ASUS M5A99FX PRO R2.0 motherboard with AMD FX-Series FX-6300 3,5GHz Socket AM3+ processor. Nvidia graphics card to get HDMI, Corsair 750W power. Very disappointed at first startup when nothing happened, blank screen and no signs of life except fans running. CPU voltage measured at 12v. What could possibly be the problem? What can I do? Never experienced total failure before. Replace CPU? Mobo says RAM OK.