First Build: Computer not recognizing peripherals

[MisterOpra]

I just built my first computer (everything was the same as Linus's "Game On" except I got a z87 Pro instead of a z87-A. Ive plugged everything in finally and I am getting a "There is no signal coming from your computer. Press any key on the keyboard or move the mouse to wake it up. If there is no display, press the monitor button now to select the correct input source on the On-Screen-Display Menu" message on the screen (Dell U2414H). Simultaneously neither my mouse (Corsair M45) nor my keyboard (Corsair K70) seem to have turned on with only a glimpse of color on the mouse when I first plug it in before the backlight shuts back off. Any and all input is greatly appreciated, (I currently have both a mini Displayport and an HDMI cable connected the same message appears for both.)

[macpro622776]

Are there any lights, sounds or error codes on the motherboard? They could give you an idea as to what is wrong.

[ManIkWeet]

Your issue is not very clear, but if your peripherals flash for a very short period of time after you press the power button, you probably connected something incorrectly on the motherboard or graphics card.