While you wait for answers, we may have found some information which could help you.
Click here for Answer Bt Messagestelephones?
how do i record a telephone conversation on a bt synergi 5500 cordless anse?
Permanent engaged tone on BT Studio 1100 handset?
BT Studio 1500 triple set?
how to repair BT 3500 Studio phone base (Master) unit?
how can i fix a bt graphite 1100phone?