OS X. After Sierra upgrade usb hub not working

Several months ago I upgraded to MacOS Sierra. As a side effect(bug?) my Sitecom usb-hub, holding 7 ports having it’s own power supply, disappeared from the mac. I searched for the internet for a solution, but there weren’t many answers. Also most of the answers concerned other brand usb-hubs. None of the answers helped my out. If only I read which computer usb ports not to use in combination with by it’s own power supplied usb devices, I wouldn’t have lived with a rather immobile keyboard on my desk that long.

Which USB port you connect to?

You can’t call it a bug actually, so Apple is not paying much attention to it. Something I can understand after the root cause of the malfunction became clear. Only Apple could provide better information on the subject. The problem occurred significantly more after updates. I still don’t fully understand it: I can draw Ohm’s law but that’s it for me on usb electrical level.

I think the problem of disappearing usb hubs has it roots different kind of usb ports on your mac and the way mac saves your hardware and personal configuration. One usb port does supply power to another usb device, another port on the computer doesn’t. If your usb hub is connected to a mac usb port that does supply power, the hub will not use it’s own power supply/adapter leaving to less electricity for the other ports to function.

Shortest most general answer

Shortest and most general answer is: When using a USB hub which has it’s own power supply, connect it to a computer’s usb port that doesn’t provide your usb hub with power/electricity.


A somewhat longer answer. Maybe I performed some ‘voodoo’ actions -e.g. restart or unplug absolutely not contributing to the solution. This had to do with mac in the background saving your personal and hardware profile after restarts. Just in case I used the third from the right usb port on the mac mini, I could use my keyboard via the hub immediately after restart. As stated: To have your usb hub working using it’s own power supply you must use a usb port on your computer that doesn’t supply the hub with electricity. The steps you have to take.

  1. Turn off your computer.
  2. You have your (apple) usb keyboard plugged in the hub. Next to the keyboard you plug in -preferably- a memory stick. Plug in the hub’s usb cable using mac mini’s  third usb port from the right usb port -sorry. too much wires, fragile hdmi to disconnect so no pic available.
  3. Plug in the electricity cable again and start the computer. Your keyboard will be working and your usb memory will start flickering as you enter mac login screen.
  4. Login, notice the second connected usb device functions as well. The memory stick (OS X format otherwise it is rejected) is mounted.
  5. Stick a third usb device in your hub and check if it’s working. If not: In case your second device was a memory stick eject or unmount it. Don’t remove the stick from the hub and don’t disconnect the usb hub from it’s power. Do unplug the hub from the computer usb port.
  6. Plug in again in the same usb port. Now both memory sticks should appear in Disk Utility. Maybe in your Desktop depending on your personal settings. Now if the Hub’s third usb port works, the other ports should work as well.
  7. Again, restart your computer to check if it is still working. If not step to the next usb entrance on your computer until you find your combination.

It is possible to switch back to the power supplying usb port on your mac mini for wiring or spatial reasons, but why should you? Keep those two right usb ports for external devices that lack their own power supply and everything should work just fine.

I use a mac mini, you may use a powerbook or have a Belkin hub confronted with another layout of USB ports. Then you do have to repeat the above steps on another usb port on your computer until you found your specific combination. For convenience matters: Start with using the keyboard and one memory stick connected to hub.