MSI Z87-G45 Bios problem

I have a MSI Z87-G45-GAMING ATX Motherboard with a i5 4670K which we had sitting comfortably at 4 Ghz Now its back to 3.6
When I boot the computer and press del or F11 it won't go into to BIOS

 

USB or ps2 keyboard
Is the keyboard in a USB 2 port, straight into board?

Tried removing parts such as disconnecting HDDs etc

Sent from my Nexus 5

 

USB into board. It worked perfectly previously

 

Try changing over the USB port, that may do the trick.

Which Del button are you using? The one nearer to the Enter key or the one on the num pad? Try both of them and see if either will get you in. Hold the Del key from the moment you power on the rig, or spam it furiously, the choice is yours.