USB Ports only work intermittently

Hi, this is my first time posting in these forums.

For about a week now I've had problems with the USB ports on my HP G6 2230sa Laptop (Running Windows 8.1). At first the USB ports wouldn't function at all, but for no reason that I can tell, now they work intermittently.
I only have a few USB devices with me, and the device I'm using to test the ports is my Microsoft Xbox 360 Wired Controller. (Although I am also testing a USB Flash Drive, a wireless mouse and a cooling mat.) Sometimes the controller lights up as soon as I plug it in, sometimes it takes a few minutes for it to be registered. The longest its actually worked for is about half an hour, but often it lights up for only a few seconds, before it loses connection.
I've tried refreshing the system (and reinstalling 8.1- took me two days), uninstalling the USB host controllers through device manager, disabling "selective suspend" in the power settings, and reinstalling the device drivers for the Xbox controller. Alas, nothing.
The above applies to the two USB ports on the left of the laptop. The one on the right is totally unresponsive. I'm not sure, but I think that one is a 3.0 port, while the two on the left, that work at times, are 2.0.

Does anyone have a solution/experience of something like this happening to them?
Any help would be much appreciated.
Thanks for reading!