I just finished replacing the battery in my iphone 3gs. It booted up fine and was ok for a few minutes. But then it suddenly rebooted and now it just randomly reboots, usually about every 10-30 minutes. It was a total pain the a$$ replacing this thing and I don't recommend anyone try it. But my question is, should I put the old battery back in or is my phone just screwed now for some reason. Is it possible that the new battery is faulty in some way and causing this problem? i followed the instructions on this youtube video and it seemed to go smoothly other than getting the thing back together. http://www.youtube.com/watch?v=Pr6HWZa0dGM
It sounds like a grounding issue. Check that the screw near the charge dock is tight. Also check the copper tab next to this is making contact with chrome bezel. Check that connector 6 is plugged in properly. and lastly, check that none of the metal tabs from the volume control have been bent back under the mainboard. Chance are that one of these is your problem. Try lightly squeezing the phone in different places to see if you can make it switch off. You might be able to identify the problem area from doing this.
