cannot reset digiport

Followed the standard protocol for resetting but will not even return a link light. It worked right before we changed over to a new network — our 3rd party application vendor was able to change 2 of the 3 digiports over, but not this one. WE have worked for about 4 hours trying to reset it, and make it workable - we cannot scan for it with the software, we have tried different networks, different cables, directly into a switch, resetted it maybe 10 times but still cannot get to it.