My USB port gives power to devices, but does not receive a signal. Please help.

[scoldedbard]

As of yesterday, one of my USB ports (of which I have two) did not go completely dead, but stopped receiving data. So I can plug in a small thumb drive, and the thumb drive receives power (I know this because it lights up), but the drive will not appear on my desktop. Same thing happened with my tascam audio interface when the interface was working, it was powering my microphone and everything and working, but my mac said it could not find any such device.
Of course, I can just plug it into my other USB port and all these devices work perfectly. But I would like to have both my USB ports working and live.
So the question is:
Is there any internal hardware configurations that I can tweak to get my USB port responsive again? Or do I need to go the mac store and have them fix it?

 

[techound1]

It's a long shot, but it's free: try resetting the SMC http://support.apple.com/kb/HT1411?viewlocale=en_US

Because one works and the other doesn't, it really seems to be pointing to a hardware problem and if it is, it will probably be a logic board replacement.

 

[scoldedbard]

K, I followed those instructions and it's working again. *PHEW* I'm sure replacing a logic board ISN'T cheap.
Thank you!