Why do my USB ports not work?

Hello everyone,

I have a Macbook Pro early 2011 edition running under Mavericks operating system. I have installed new RAM memory (16GB) and a 1 Terabyte hard drive I purchased through Crucial.com. I am also running Parallels 2.0.1 and everything works very nicely.

I recently began to notice that my USB ports were becoming more and more unreliable recognizing USB devices randomly. I am now to the point where the devices connected to USBs on the machine are not recognized at all. I did notice that the USBs are sending power out to the connected devices but it never shows an icon on the desktop for connected devices as usual.

Some of the recommended solutions I have tried are: Resetting the SMC and resetting the PRAM following the methods describe in different Mac forums. Note: these methods (resetting SMC and PRAM) seem to have help others and at some point they work for me, but at this point these methods do absolutely nothing. I even open the Macbook and disconnected the battery as a way to drain the power off the internal circuits (total power reset) but I had no luck at all. My USB ports still don’t work.

I have taken the machine to the “Genius Bar” at the Mac store and their only solution was to replace the Logic board all at once for $280. My past experiences with these “Geniuses” has been less that good and I really do not thrust them. I have fixed problems on my Mac myself that they render impossible to fix without making me pay for a new part and labor. In other words it seem to me that they only replace parts and never troubleshoot problems properly.

Does anyone here at iFixit. com has encounter a problem similar to mine? Has anyone been able to locate or replace bad components on logic board that can fix this problem? Please know that I have experience replacing integrated circuits and troubleshooting circuits elements down to individual parts such transistors, resistors, etc…

Thank you,