I have a customer with a acs r3.0.
The co lines flash red like the is in use, but if the customer picks up you get the recording that you get if you go off hook and don't dial. the problem floats from 1 line to other no pattern at all. the system has 4 lines in it. Have had qwest out once and they found a short on one pair and fixed it they say ? that the rest are working fine. I have checked programing, move lines to other co ports, checked wiring, I still think it is a qwest issue. I have not see this on a partner before ?
Thanks
Jeff

It does sound like a short, to be sure I would disconnect the lines at the Dmark and test with a butt set that way you would know for sure.

could be RF interference nducing phantom ringing or hold.

Or it could be a short from on the wire to the phone or a malfunctioning phone. look for a phone with a green light.

The Partner ACS system phones don't show a red light from a short on the CO lines before the equipment. Since its occurring on two lines check all your system phones for a held up conference. Also check single line sets, if any for offhook condition. The only problem I can imagine from the teleco's switch that may cause your problem is that you are getting an external call, the calling party disconnects but the CO never sends a disconnect to the Partner. You can prove this by plugging a single line phone in at the dmarc and have someone call you on the affected lines.