Hello & Welcome to Just Answer,
Sorry to hear of the issue you are having with your phone(s).
May I ask:1) can you VERIFY the FULL Make & Model Number of the phone system you are working with?
I only ask because that looks something like the model for a cordless handset, but I'm not finding an exact match.
2) Is this an "add-on" handset - for a cordless system?
I see it has been a few days and I just wanted to follow up to see if you have any more questions concerning this issue or if the issue was resolved.
I look forward to any further questions or results that you may have.
Thanks, ***** *****