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I bought an active 7-port-USB-Hub to avoid all the cable mess on my desk. The following devices are plugged in:

  • Scanner (which is not being used, actually)
  • Keyboard
  • Mouse
  • Android-Phone

When I now plug in a hard disk (passive, 2.5') as Time Machine device, it is not recognized. I wonder why this is the case, because it's an active hub. Do I really need to buy a hard disk with its own power supply?

Another strange thing is, that when I plug the hard disk directly into the MacBook (beside the hub), it does not work either.

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3 Answers 3

up vote 5 down vote accepted

I believe the key here, is that he stated it's a passive 2.5" hard drive enclosure. That means that it may require two powered ports to have full power. The hard drive just may not be getting enough power.

  1. Is the hub plugged into a power outlet
  2. Does the usb cable have two ports? And are both being plugged into the usb hub?
  3. Does system Profiler see the drive?
  4. Does Disk Utility see the drive?
  5. What's the make & model of the USB Hub?
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Right! Didn't it come with some "Y-cable" like cooldrives.com/usb-power-cable-mini-b.html or pccables.com/cgi-bin/… ? Or do it yourself: google.com/search?q=do+it+yourself+usb+y-cable –  Arjan Oct 16 '09 at 11:00
    
thanks for your suggestion - i borrowed such a cable and will now check and give feedback later. –  schneck Oct 16 '09 at 12:19
    
that solved it, thanks! –  schneck Oct 16 '09 at 16:04

Looks like the problem is not the hub but the disk.

If it is visible from Disk Utility, try to format it with an HFS+ filesystem and a GUID partition table.

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It's already formatted with HFS+, and it sometimes appears that the mac recognizes it, and sometimes not. The hub was not cheap, and i'd wonder if the problem sits there. –  schneck Oct 16 '09 at 10:22

This does not explain why it won't work with the hub, but on the MacBook itself, all USB ports aren't created equal.

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