This happened to me at the Apple store when they replaced my cracked screen. Granted, I have a 3GS, but I assume the wire connection is similar in the i4. Anyway, at first, he gave me back my phone, and everything looked great, but he asked me to make a phone call just to check. Sure enough, the person I called couldn't hear me, so the technician took the phone back. 10 minutes later, he came out again, and he said that the wire has to be plugged in really tight or else the speaker won't work. I think you just have to go in again and make sure the wire is plugged in securely, and you'll be ok.
10-26-2010 06:57 AM