Have an XTS, one extension seems to go off hook on its own (this is a classroom) and then there is some sort of feedback from the speaker phone. Customer changed out the phone, same deal. Any thoughts on why a station would go offhook on its own? Thanks

Sounds like a wiring issue or a bad port. I had one do this and it turned out the pins inside the jack were corroded causing an intermittent short. Liquid somehow got inside the jack. Change the base cord, check all of the connections,use a different pair, and if that doesn't work maybe change the port.

Thanks, will give it a try.

Bad jack, not usually a bad port when experiencing these symptoms.

To add, if it is a digital station, you really need to make sure that the jack is only wired to the green/red pair on the jack (pins 3/4 on a 6P6C jack or 4/5 on an 8P8C). The second pair on digital sets was meant to interface outward to external devices, such as Wanderer handsets, etc. A long cable run, as is typical to classroom phones in a school can put all kinds of 'confusion' onto the second pair that will cause things like this. It could also be due to a physical fault on the second pair. Play it safe and just make sure that the white/blue pair is the only thing connected to a good jack and you'll be fine.

The phones and wall mount kits were shipped with two-conductor cords to protect against this (my assumption), but we all know that four-conductor line cords are the norm and this phone's cord may have been replaced along the line.