Typically when the "LED" or "TALK" on the handset stays steady, this means the cordless and the base are talking to each other, but something is preventing the dial tone to be heard.
A. Disconnect the AC Adapter and reconnect it.
B. Disconnect the battery and reconnect it.
C. Place handset on base, let set for 5 seconds. (Resetting Security Code)
D. Replace phone cord with one that you know for sure works but first were you using the phone cord that came with the unit?
E. Move phone to different phone jack in a different location.
F. Press volume control on the handset. As you press the volume button up and down, listen for a hissing noise. If you hear this, then the speaker is ok. If no noise is heard this could mean the handset speaker is defective and the phone will need to come in for repair because there is no audio.
G. Make sure phone cord is not plugged into a splitter, fax, computer, remote answering machine or caller ID box.
H. Try the phone in a different location all together.
I. Are you using an extra long telephone cord or have it plugged into an extention?