Hi Matilde, how long have you been having this problem with the ringer? If you are sure that you have already turned the volume all the way up, then it's possible that this problem has something to do with the hardware of the phone itself. Try to get into the Settings menu and look for the audio profiles to make sure that the phone is on one that has sound (i.e. not Silent or Meeting mode but General or Outside). I hope you find the fix for this there!