PC BUILD_ No beep, no display on boot-up. Help?

Hello,
I built my pc a couple months ago and everything was working perfectly. Two days ago my mobo got fried cause i plugged in a fan(external case fan) incorrectly, so i bought a new one today. (same model, 'asus maximus IV'). Now when i boot up, all the fans spin but there is no boot and no display on the screen. The LED on the mobo says "00". Also sometimes when i boot-up the fans spin for 2 seconds and then stop. I have tested the cpu, the power supply, and they RAM, and they all work. (they worked perfectly a before my 1st mobo got fried). Do you think this new mobo is faulty from the store? or am i doing something wrong?I EVEN GET NO BEEPS WITH NO RAM INSTALLED. I just tested it out of the case with no RAM, just cpu and power supply, and the same thing happens, "00" on the LED and it turns OFF once and then ON again by itself. Then it stays on (fans spinning etc) but does nothing, NO BEEPS AND NO DISPLAY. What can i do about this??? Please help