What has happened is the mini-USB port has either come partway or completely unsoldered from the motherboard.
On the back of the port there are finger-like pins that have to connect to the main board to transfer the power. When one or more don't connect anymore it wont work.
It can be repairable but without the proper tools and training you'd be better off taking it to a repair shop and have them fix it. Give some local shops a call to see if you can get some quotes.