iPhone 3G Ear speaker and Sensor Problem

Same thing is with me I think ribbon 3 is the problem.

If your proximity sensor, and ear speaker is not working, then you most likely have a damaged #3 ribbon. This can be replaced fairly easily. The ribbon can look flawless yet still be damaged FYI. I replace these all the time for customers

http://hectordtruong.blogspot.com/

Ribbon 3 is a different animal: I thought I broke mine taking it apart, because I couldn't see exactly how it came apart, plus I expected it to have a block of pins on it like ribbons 1 and 2.... but it doesn''t

The ribbon inserts like a blade, and the little lever thingy locks it into place if the ribbon is fully inserted. I used a pair of plain tweezers (tips padded with scotch tape) to finagle it together.

The parts are so small it doesn't seem possible.

Think of the connectors on the back of a stereo: where the bare ends of the speaker wire push in and get locked down with a lever tab.