I have a small Norstar 3x8 KSU with standard punch down block. I connected an M7310 phone to the first pair on the block (blue-white, white-blue) and all the 7310 would do is display an arrow on one key which slowly fades, nothing else. I connected an analog phone to the first pair and got a tone that sounded like a pbx dial-tone. The KSU appears to be on the old side (maybe around 1990).
Is there a problem with the KSU? Or maybe its the phone. It would do the same thing when I tried an M2112.
Any help is appreciated
Thanks.

-Drew

Drew,try hooking the M7310 up to the white/orange pair and see if phone works on that port.

I get the same results on the white-orange pair as well as all the other 8 pairs. I only connected the two tip and ring leads from the phone to the patch panel, I am assuming the yellow and black are unused. When connecting the 7310 to a normal analog line it will do the same thing. Is the KSU normally supposed to emit a tone?

The tone you are hearing is probably intercom tone , It sounds like your ksu has had it , or maybe it has power problems. But openwire will be able to help you more on Norstar

Drew,contact me direct by email please.
[email protected]

Drew,I am curious to know....was it a bad ksu or set?
Bruce