Yesterday I recognized that the latter USB port doesn't seems to be broken. I tried to sync my iPad, but it got no connection the the MacBook. Even the
dmesg log showed no activity after connecting any device to the USB port. The front USB port worked without any issues. What first seemed to be an hardware issues turned out to be a interesting foible of the MacBook family. To cut a long story short, the port isn't broken. I found the solution somewhere on the internet but don't know exactly where by now, so thanks to the original author on this way.
I can't guarantee that it will solve your issue but it's worth giving it a try:
Initial state: MacBook Pro running without any applications running. Be sure you backed up all your data just in case.
- Simultaneously press Shift + Ctrl + Option
- While holding shortcut of step 1, press the power button -> Device turns off immediately
- Turn on the device again -> OS X starts with an additional progress bar - this could take a moment
- The system starts in safe mode, the USB port should be working again by now
- Reboot back to normal mode
Now everything should be working again.