my gf's 3g iphone's headset stopped working, no audio comes out of any earphones we plug into it. we tried blowing air into it but that did not fix the problem. I know she installed os4 on it but i doubt that caused the issue. this 3g is a year old, she doesn't have any warranty on it but wants to have it fixed if its not too expensive, she rather not buy a new iphone she is still happy with it. does apple store do repairs on this issue. how much do you think it would cost?