This is my first post and I apologize if I break any rules.

We have a DK424i (RCTUA PCB) system that (without going into much detail) lost it's configuration and I am having to reprogram. Everything seems to be working correctly except that my Program 81/87 (CO Line Station Ringing) isn't working correctly.

I have it programmed to ring all extensions immediately in both dan and night modes but the systems doesn't respond this way. It rings station 200 (only) in day mode and 201 (only) in night mode. I can verify that my Program 81/87 settings are correct but don't know what gives.

I have searched this forum but have yet to find an answer.

P.S. All Co lines appear on all extensions. Buttons flash red, however when there is an incoming CO line call (but no ringing).

Please help, I'm desperate.
Darrell