Wont charge after screen repair

I replaced the touch screen and back panel. The iPhone worked fine before it just had a cracked touch screen. after replacing the broken screen the phone works great however, it wont charge or recognize itunes when plugged into the computer. I have power cycled the phone, opened it up again and made sure all the connections are clean and plugged in properly and it still wont charge. If the phone is off when I plug it in it will turn on but wont show that it is charging. The only thing I can guess (after looking online) that is wrong it a fuse may have blown during the repair. When I removed the batter the first time I did notice a tiny spark by the connection, but I could see no damage and the phone works properly in all aspects except charging.

Any suggestions?