Strange problems with USB ports?

My USB port suddenly stopped working one day. After letting my laptop sit for a day though, when I plug in my computer fan, it's perfectly fine, but when I plug in my USB mouse too, it suddenly stops working again. But it seems to reset whenever I turn my laptop off. So I tried USB Mouse first then plugged in my fan, and it worked for a good while, but then shut off again. Is it an overload or something? It never had any problems before, so why now? Does anyone have any solutions as to what could be the problem?