asus sabertooth z77 questions/help

[pokettomonstua]

hi, Whenever i plugged things into the usb 3.0 my boot up time increased and my monitor don't display anything or it goes to sleep.
why does this problem occur? any opinion and solution please!!
mobo bios version is 1504
Thanks in advance!

 

[alexoiu]

Hi, back or front port?