While you wait for answers, we may have found some information which could help you.
Click here for Flashing Base Unithow do i record a telephone conversation on a bt synergi 5500 cordless anse?
Permanent engaged tone on BT Studio 1100 handset?
telephones?
Beeping phone BT Studio 1100?
bt 1100 twin need to replace broken 2nd handset?
Bt 3500 cordless tel/answerphone?