Hello all!

I have an old AT&T Partner system with two 206E cards, four CO lines, and eight extensions. Recently I've noticed an odd problem: when any of the CO lines are ringing, a "pulsing" type noise can be heard on any of the extensions connected to the second 206E card.

None of the extensions on the first card are affected, and the noise is not present if I plug a regular phone into the CO lines. I also tried swapping some of the extensions between the cards (to rule out inside wiring as the cause).

Any idea what might be wrong here? I'm not an expert on these Partners, so please forgive me if this is a newbie question.

--Keith