i have an iphone 3gs and having problems with the ringer. i tried resetting but that didnt work. i dont know why but the ringer sometimes works and sometimes doesnt. I have the ringer all the way up and it shows that its up but nothing
You state it is random, but can it be narrowed down to specific contacts? It is possible to set a custom ringtone per contact, and if the issue is with specifc contacts, I would suspect the ringtone associated with those contacts.