There are many causes why the call signal may not function correctly on a Partyline system
Cause 1: Excessive DC loading of intercom line.
Solution 1: Remove any audio transformers or other equipment which may be connected across the intercom line. If equipment other than Clear-Com intercom equipment must be connected to the intercom line, please contact Clear-Com application or service personnel for advice.
Cause 2: Far too many terminations on the intercom line.
Solution 2: Check all Main Stations and Power Supplies to make sure each intercom channel is terminated at only one point .