My iphone's earpiece hadn't been working for a while however the proximity sensor still worked. So I decided to open it up and try fix it. I thought it might be the ribbon cable so I unplugged it and replugged it in. However when I turned the iphone back on this time the proximatey sensor didn't work either. So If i'm looking to buy new parts should I need a new ribbon cable, headphone jack or new 3g earpiece? Any help at all is appreciated. Thanks