I imagine you are talking about the power connector, which can be seen in this photo:
http://guide-images.ifixit.net/igi/5WFTBBBydtHHsdRY.huge
... bottom right, immediately below the vibration motor.
It's a surface mount component. If the board where it connects, and the loose power socket, are both undamaged, it probably could be resoldered back on with a hot air gun and a lot of care, much like soldering in SM IC's. A soldering iron will not be able to do this, it will just mess everything up. If you don't have the tools to repair this, a good repair shop could do it for you.
err, here is an amateur showing how it's done.
http://www.youtube.com/watch?v=yhhLyxkTVQI