So i have dozens of 8520's in house, they've all got 6 pin RJ ends but only use 4 (if im understanding-sorry, im not a phone guy). Ive got other phone cords here that only have the 4 brass punchdowns and they dont work. can i re-wire them to work? What's so different about these phones?
They only use 1 pair, but on pins 3/6 instead of 4/5.
Just to Add Clarification to those who find this thread in the Future.
On a 6 or 8 Pin Jack. Traditional Modular cords use the Inner most pair. This is the White/Blue pair. Axxess phones like your 8520 use the 2nd pair from the middle. This is the White/Green pair on TIA 568B wiring. This is the White/Orange pair on USOC and TIA 568A wiring.
USOC Orange Pair
https://en.wikipedia.org/wiki/Modular_connectorhttps://www.phonegeeks.com/phjawicoco.html
We need to add to this that the phones are polarity sensative and the line cord that came with the phone had a reverse between the two ends. That is to say pin2 went to 5 and 5 went to 2.
They use the black/yellow or orange pair on 6P6C or green pair on a CAT5