Bell Circuit Trouble on XRF

[CVFPLLC]

I'm having trouble (being somewhat new to the industry) identifying why I'm receiving a bell circuit trouble on an XRF 690F. Any help and ideas are greatly appreciated. Thank you.

There are 3 auxiliary panels to cover 7 units in this building. When I put a 10k ohm resistor on the panel the trouble clears. I've found 4 EOL's and each is good. I must be missing an EOL, have a bad aux panel, or bad wiring somewhere in between. Thoughts?