There are definitely some wires off somewhere, or you've actually missed a switch. The unit should also absolutely start up in "Standby" mode. If the display is blank then the device is either turned off (at control head) or not powered up.
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
1984 Fast/Nicholson 345 "FastForward"