I have repaired several of these, including my own. What has happened is that the socket is a surface mount type and there is no mechanical strength in the soldered joints making it easier for them to break.
Ideally the socket needs to be removed and replaced professionally, but I have found it possible to repair these sockets by doing the following:
Get a good soldering iron with a very clean tip. It is important that there is no loose liquid solder on the tip. From the top of the socket, heat up each contact by pushing the hot soldering iron tip against it. Very gently wiggle the contact, and when it moves freely (after no more than 3 or 4 secs of heating) move to the next. It is a good idea to reheat all the contacts on the socket, as I have found pins that seem firm can still make poor contact with the PCB.
It goes without saying you need to take anti-static precautions and that you need a very steady hand. Don't over heat! The socket itself is plastic and can be easily melted.
This reheating method works because there are flux residues remaining on the soldered joints from when the board was made, this flux residue helps the resoldering process.
