Did you just replace the battery? Did it ever start with the new battery and the dock connector? Did you double check, no triple check your work? Does iTunes recognize it? Try to reset the iPhone by holding the sleep/wake button at the top right of the device and the home button at the bottom center of the face at the same time. Hold them both until you see the screen go black and the white Apple logo appear.Once the logo shows you can release the buttons. Good Luck and let us know how it is progressing.