We may have found other answers which could help you.
Click here for Phone Cordless Reset
TAM FULL on Binatone 1420 Single, base holds old messages th?
Problem with handsets?
How can I mend my BT4600 (1+1) phone?
BT Studio 4500 cordless telephone?
Bt 4600 phone?
How can i get my handset to speak with the caller?