Poor signal probably means what it says. Try a different cable.
You could also try connecting the Eclipse AES input to its AES output (while still synched to word clock) and see if this says the same – if it does, you may have a hardware problem.
I assume that you have set up the Eclipse to sync to Wordclock (SETUP/Digin/CLOCK) and have set the unit to receive AES in (SETUP/Digin/DIGIN).
