Hello & Welcome to Just Answer,
Sorry to hear of the issue you are having with your phones.
To help you with this issue, may I ask:1) How many TOTAL handsets do you have with this system?2) What phone service provider (phone company) you have for this phone line?3) If you have ANY other devices (phones, fax, alarm system, etc.) attached to this same phone line (not part of the MAIN system), and if so, are they working properly?
4) WHEN did this issue first begin (or was noticed)?