I have a KX-T7880 (connected to a KX-TD1232) that has worked fine for several years. Now when I power it on and press talk, it beeps twice. Then if I dial just about anything, the main phone extension on the system rings. Ditto if I just press a button for an outside line and press any number button.

The battery is fine. Any other suggestions on how I can debug or repair?

thanks...Mike