This indicates that the call is actually received but since there is no ring, no one picks up, channeling the caller to your voicemail. To solve this:
- Check whether your ring volume is not too low or your phone is not muted.
- Check whether your phone set is connected to the right phone port of the phone adapter. The Phone 1 port should be used in the first place, and Phone 2 is used only if there is a second phone line or a fax line. To check whether your phone is connected to the right port, lift the receiver and press 'Talk' or 'OK'. If the Phone 2 port lights up, your phone is plugged to the wrong port.
- It might also be that your phone's loudspeaker, normally found inside the casing, is damaged or has a wire loose or a welding undone.