AT&T CL80101 Cordless Telephone User Manual

My cordless handset does not ring when I receive a call.
Make sure that the ringer is not off. Refer to Ringer volume
in the user’s manual provided with your CL81101/CL81201/
CL82601 telephone.
Make sure you plug the telephone line cord securely into the
telephone base and telephone jack. Make sure you plug in the
power cord securely.
The cordless handset may be too far from the telephone base.
Charge the battery in the cordless handset for at least 10 hours.
For optimum daily performance, return the cordless handset to
the telephone base or charger when not in use.
You may have too many extension phones on your telephone
line to allow all of them to ring simultaneously. Try unplugging
some of the other phones.
The layout of your home or office might be limiting the
operating range. Try moving the telephone base to another
location, preferably on an upper floor.
If the other phones in your home are having the same problem,
contact your telephone service provider (charges might apply).
Test a working phone at the phone jack. If another phone has
the same problem, contact your telephone service provider
(charges might apply).
Other electronic products such as HAM radios and other DECT
phones, can cause interference with your cordless phone. Try
installing your phone as far away as possible from these types
of electronic devices.
Completely remove the battery. Replace it and place the
cordless handset into the telephone base. Allow up to one
minute for the handset to reestablish its connection with the
telephone base.
Your line cord might be defective. Try installing a new line cord.