I just came from a new client who told me Comcast had verified their line was good to the interface so it was their problem.

Truth is that they have a 308 doorphone so I explained that it is a system device and nothing to do with Comcast. They have no display sets and my book was home so I'm returning next week to see if the software went flat although I thought default was all doorphones ringing all stations?..

I checked the IW as good and suspect the adapter at the KSU has failed

another clue.
Neither doorphone has any talk battery but on only 1 pressing the call button delivers DT?

Does anyone have a way for me to determine if it is the adapter without buying one to swap?

Thanks