HDBT Output port on 8x8 Matrix won’t link to receiver

[cole.clark]

I have a C4-8ZVMS-B 8x8 vid matrix and one of the HDBT output ports refuses to link to a receiver over a run of cat 5e > roughly 20ft.  It had been serving a receiver that was on a fairly long run (90+ ft) but now the link light on the receiver flashes sporadically.  If I take that same receiver and connect it to the port over a short Ethernet cable it will link immediately.  I have tested the 90ft run by connecting it to a different port on the same matrix and achieve a link w/o issue.  I’ve tried spare receivers and they all exhibit the same (link fine on that port over a short run; won’t link over the long run).  I’ve tried rebooting the matrix but have not done a factory reset (as I am concerned I’ll lose configuration information I won’t be able to restore w/o my installer logging in (and it has been a holiday weekend).

My question is - if I replace the video matrix with the same model is there anything in the matrix itself that needs to be configured, or is all of the configuration information in the Controller?   I assume something has partially fried that particular output port.