Your next option would probably be wiring in the eye box then the input card. I don't know how familiar you are with the eye wiring so don't know if this is helpful but basically it has to be the receiver eye, the cable, wiring in the eye box or short in the wire to the ID16(low probability but possible), then off to the input card.
You can emulate a eye test by flipping the lever on the transmitter eye relay located in the gantry and watching the appropriate lights on the ID 16 2010 inputs 11 and 12, or you can view the eye inputs in the tech menu while you manually start a wash, then reset, then repeat over an over. When I experienced this in the past it was often the first wash of the day.