So my motherboard died 3 months ago, and today I finally got the replacement. It is a Z77 Extreme 4 ASUS motherboard. Upon hooking it all up, it told me the vga had no signal. I plugged it into my motherboard and it wasnt working. Curious to find out whether the rear I/O panel was working, I conducted a iphone test. I put my charger on the usb ports on the back while my computer was on, and tested each one plugging the charger in my phone, none of them worked. This is also the reasoning for the vga to not work since no power is going into the rear I/O panel. The motherboard is brand new, I suspect no problems with it whatsoever. All lights and fans are working, even the mouse and keyboard dont work on the back I/O panels.
Check that the io shield not shorting out the motherboard. If something took out the old mb it may be what plugged in now. Try just a keyboard and Mouse and video. If there no change try the mb outside the case. If it still screwed up the old mb may have killed the CPU.