I found seven Ethernet ports on an operational polar icebreaker with badly deformed contact pins. The affected pins also look corroded, even though the switch is not especially old and the equipment room is temperature- and humidity-controlled. I'm trying to determine whether this is more likely physical damage from an incompatible connector, rough cable handling, or corrosion caused by the vessel's environment.
4 Answers
The most likely physical cause is someone forcing an RJ11 telephone plug into the Ethernet jack. It is close enough in size to enter the port, but its narrower shape can push specific contacts out of alignment. A damaged or badly manufactured RJ45 plug, or a cable being yanked out at an angle, could cause similar damage.
If the switch is disconnected and fully powered down, gently compare the damaged jack with an intact one. In some connectors the contacts have simply jumped out of the plastic guide at the rear and can be nudged back with a very fine tool, but corroded or permanently bent contacts usually mean the jack or switch should be replaced.
It is also possible that someone inserted something other than a network plug, such as a USB connector, or used a tool to clear a stuck cable. If all seven ports have the same pins bent in the same direction, look for one repeated action or an incompatible connector rather than random failures.
The corrosion may be a separate environmental problem. Salt-laden air can reach conditioned equipment spaces on ships and cause galvanic corrosion, especially around PoE contacts. A controlled room does not necessarily eliminate the effects of marine air. Inspect the other ports, plugs, and patch-panel hardware for similar oxidation.

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