Hello,
Our customer has a 6 year old TDA50G that had multiple digital station ports that quit working.
On Aug 10th 2 consecutive ports on the second 5172 station card quit working X117-118.
No display on the phones, no lights would work except the MW light would stay on.
Replaced the card with new and they worked fine.

Two weeks later one of the ports on the first 5172 card quit working X101.
Same as above.

Now two more weeks later one of the original ports that quit working on the second card, quit again X118.
Total time this port worked after card was replaced was about 4 weeks.

These ports themselves quit working and do not work when a phone is plugged directly into the 5172 card RJ11 station ports.

These extensions are serviced by a 4 year old underground cable and reside about 350ft away from the KSU in a different building.
This cable does have lightning protection on each end of the cable and is run in conduit between the buildings.

I plan to examine the the cable terminations and test resistance on these pairs on my next trip out.

I was mainly interested in finding out if the 50G systems have any history of station port issues as they got older.

We installed a number of these 50G systems through the years and so far have never had a port go bad on any of the others.

I do not see any corrosion on either of the original 5172 boards or connectors but there was some dust inside the cabinet.

Any suggestions would be Much appreciated! Thank You!