Check for any loose connections and make sure the phone has been installed properly. For the Installation instructions, refer to our quick installation guide. Check whether dial tone is present in one of the audio modes.
Switch between the handset, headset (if available) and handsfree speakerphone to check whether the dial tone is present in one of the audio modes. If the dial tone exists in another audio mode, connect a different handset or headset to isolate the problem.