Asus Motherboard A2 Error, computer won't turn on

[UnknownOtter]

Specs:
Asus Maximus 6 Formula
Nvidia GTX780TI
intel 4770k

I just reseated my GPU to try to fix an error. Now, however, when I try to turn on the computer, it turns on, goes off, turns back on but the fan slows after a second. The monitor activates, but says it doesn't detect anyting and goes back off. Finally, my motherboard gives me the A2 Error, which means IDE detect on the manual.

 

[alexoiu]

Can you connect the monitor to the HDMI on the motherboard (graphics card removed)?