Need alternative power source for fan

I was monkeying around doing some work on my MBP and I broke the socket on the mother board the left fan plugs into. Tried to re-solder. Tried using a conductive pen. Tried hard-soldering the wee wires to the MB, all to no avail.
Ultimately, I connected an old USB cord to the fan, ran it out the back to plug into a USB port. It's okay, but I have to plug it in and unplug it all the time because it keeps running when the MBP goes to sleep. And although I don't go mobile that much, it's a pain when I do.

Does anybody have any suggestions as to how I could fix this? I don't know that much about effecting repairs to solder joints on circuit board, but I am willing to learn.