studio fiber converter

I have 4 brand new out of the box URSA 2 camera chains and i can not get the CCU to talk to the camera thru the SMPTE fiber. it powers okay and there is a shot in the viewfinder but no fiber connection. I have tried all four chains and am using new SMPTE cable as well.. is this a set up problem?

Personally I haven't worked with these yet, but Sony and other CCU manufacturers sometimes have a switch that turns the lasers on for the fiber. Had a CCU with "SW 1" to power on lasers to the camera.