By connecting appears ASROCK logo and the keyboard does not work, you can not enter the bios.

Motheboard Asrock G31M-VS2 Rev: G/A 1.01

USB keyboard doesn't work either?
The problem may be,as in Multicontroller,and the southern bridge.

also the keyboard usb not work.

Try a known good power adapter.
If disconnected from the Board all the periphery and inserted only the processor and memory,there is a voltage of 5V on the USB and PS2 but the fee remains hanging not responding to the keyboard,it is likely a faulty South bridge.
You can try to change the Multicontroller,but I think it will not help,although in my practice there was a case hung from Multicontroller,not responding to the keyboard,as you have.
Processor supported motherboard? Previously worked with him fee?