I recently replaced the screen on my iphone 4 verizon phone, it would only turn on if charged though a wall port, kept searching for service and read 100% battery. when unplugged it would immediately turn off and could not be charged by my mac, also the screen would freeze every minute or so and automatically restart... I took the back off of the phone, took out the screw for the battery connector and pushed REALLY hard on the connector piece, like white thumbed myself and now..... Presto! service restored and it holds a charge. Thank you for this answer!