Behringer x32 Headphones and Talkback inoperative


I am un able to use the talkback or hear any sound out of either side of the headphones jack on the Behringer X32. 

I've Factory reset the board but still have no input from the on board mic or ext mic, the monitor shows bars on the meters but no sound out.

I've also tried to route the talkback through the P16 but the prevailed nothing. 

Is there something that I am missing?