Chosen Solution

Macbook Pro 2015 running latest mac os high sierra 10.13.6. One of the usb ports stopped working out of the blue for seemingly no reason. It can still give power to a device (powers an arduino) but the macbook cannot seem to detect anything. Wasn’t dropped or anything, suspect it is a software problem. Tried and didn’t work:

  • SMC reset
  • Booting into Safe Mode
  • Trying in a different user Would really appreciate if anyone could help with a solution to this problem.

Usb ports do have power lines but also data lines. Since you tried the available hardware resets it seems to be you have a failure along the data rails. If it’s your right port it might be sufficient to replace the I/O board it belongs to. If it’s the left port, that sits right on the logic board itself and needs component level troubleshooting. The why just has one simple answer..because things break unexpectedly, that happens with cars, satellites, space shuttles and Macbooks too.