While you wait for answers, we may have found some information which could help you.
Click here for Bt Studio 1100BT Studio 1500 triple set?
Beeping phone BT Studio 1100?
Permanent engaged tone on BT Studio 1100 handset?
BT Studio 3500 base problem?
how can i fix a bt graphite 1100phone?
Bt 3500 cordless tel/answerphone?