Thankyou for your reply
I got a USB flash drive with the correct bios on it, (z77st.cap) However nothing happens with it when pressing the bios button.
I have reconnected all the wires re-installed the ram / CPU. checked there was no damage to the pins, tried turning it on with only the MB/CPU/RAM connected and nothing has worked.
There is a constant yellow LED on (the power standby light) when I connect up the power so I know it's not the PSU and that the MB does recognise it's receiving power but nothing else will turn on.
The MB manual says it has other LEDs that flash when something is not connected correctly or working as intended, Non of these are flashing.