sundance-communications.com/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems Samsung 50SI dropping calls

I have a mainteance customer with Comcast Trunks in a 50SI.They have started dropping calls. The calls drop at different times and you can hear like a buzzing sound just before the call drops. A message appears on the display that says something like "hung up" or "hang up".
I put (2) 4 line att sets and took the Samsung off line. The number of dropped calls have dropped, but they still have dropped calls every once in a while.
Is this a valid test to suggest the issue is a Comcast one or might it still be a Samsung issue and what should I do next?
Zete

Is it on all the lines? Does hapeen to all the pbhones. Do you have ant spare trunk ports? Its all trial and error

I replaced both tk-3 cards, the calls drop from all phones, I put in (3) 4line ATT analog sets and they all are dropping the calls still.
Their local "WOW" provider says that these loop start trunks will not function with analog stand alone sets so that result is not a valid test to determine where and how to fix this issue. He suggests a new phone system might be the ticket?

So a phone system that has analog trunk ports that for all intents and purposes are an analog telephone set interface is not a valid test on their loop start lines?
Sounds like it's time to find a line provider that knows what they are talking about.

PVlJ is correct You're correct Ask the providelr how to test them then?