Brand new iMac (21.5") USB mystery

Discussion in 'iMac' started by sPaCePiR8, Feb 4, 2015.

  1. sPaCePiR8 macrumors newbie

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    Feb 4, 2015
    #1
    Hello forum,

    I've been using Macs for over 10 years now, so far never had a problem which couldn't be solved but now it seems I've reached a point where this is no longer the case.

    Have a new iMac (21.5", 3.1GHz, 1TB Fusion Drive) since a few days. Everything's working fine, apart from the USB ports. A few examples below:

    - iPad working perfectly fine (i.e. charging and being recognized in iTunes) when using an original Apple Lightning cable
    - iPad alternating between "plugged-in" mode and "plugged-out" mode constantly when using a non-Apple Lightning cable (tried no name ones as well as Belkin ones - same result). The same no name or Belkin cable however works fine when charging iPad using the (original Apple) wall plug
    - iPhone works perfectly fine with no name / Belkin and Apple Lightning cable
    - 2.5" USB 2.0 portable hard drive works perfectly fine
    - 3.5" external hard drive (in case, externally powered) works perfectly fine over FireWire800 via Thunderbolt adapter
    - the same 3.5" external hard drive does not work over USB 3.0 (external case has 2 FW800 and one USB 3.0 plug). Whenever I plug it in using the USB 3.0 it appears in the Finder for a few seconds, then an error message pops up saying I should unmount the drive properly before ejecting. It also shows up in the disk utility within the first few seconds but then disappears. Have tried a few cables and all four USB ports and it's the same for all of them

    Have searched the web quite extensively, many people seem to have problems with USB 3.0 drives when the Mac goes to sleep but my problem pops up immediately after I plug the drive in. When I first tried it I thought the USBs might be faulty but they work perfectly fine with the iPhone and the old USB 2.0 external HD

    Any thoughts on this? Thanks in advance
     
  2. redheeler macrumors 603

    redheeler

    Joined:
    Oct 17, 2014
    #2
    I'd bet it's a problem with the drive itself. Have you tried it on any other machines to see if it does the same thing?
     
  3. sPaCePiR8 thread starter macrumors newbie

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    Feb 4, 2015
    #3
    I thought of that as well but as I said, it works absolutely fine on the FireWire/Thunderbolt port. Disk Utility also doesn't show any problems. The HDD inside is also just a few weeks old.
     
  4. dyt1983, Feb 5, 2015
    Last edited: Jun 1, 2015

    dyt1983 macrumors 65816

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    #4
    edit: To remove personally identifying info not relevant to the conversation.
     
  5. sPaCePiR8 thread starter macrumors newbie

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    Feb 4, 2015
    #5
    Thanks, makes sense. I will try and check on another Mac tonight.
    The USB 3.0 is a standard connector (like this one: http://www.techspot.com/articles-info/278/images/3s.jpg), not a micro one
     
  6. sPaCePiR8 thread starter macrumors newbie

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    Feb 4, 2015
    #6
    Did that and the issue is the same - seems to be a problem with the external case then.

    Thanks for your help.

    Any ideas on the issue with the iPad and non-Apple cables? Since the other error is most likely caused by the case, this seems to be another one on its own
     
  7. Fishrrman macrumors G4

    Joined:
    Feb 20, 2009
    #7
    [[ - 3.5" external hard drive (in case, externally powered) works perfectly fine over FireWire800 via Thunderbolt adapter
    - the same 3.5" external hard drive does not work over USB 3.0 (external case has 2 FW800 and one USB 3.0 plug). Whenever I plug it in using the USB 3.0 it appears in the Finder for a few seconds, then an error message pops up saying I should unmount the drive properly before ejecting. It also shows up in the disk utility within the first few seconds but then disappears. Have tried a few cables and all four USB ports and it's the same for all of them ]]


    Does this external drive enclosure have its own power supply, or are you trying to run it off of "bus power" ???

    If it has a power supply, try using it. USB3 probably can't supply enough "bus power" to run it on its own...
     
  8. dyt1983, Feb 7, 2015
    Last edited: Jun 1, 2015

    dyt1983 macrumors 65816

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    #8
    edit: To remove personally identifying info not relevant to the conversation.
     
  9. Fishrrman macrumors G4

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    Feb 20, 2009
    #9
    [[ You quoted the first sentence where the OP wrote "externally powered" ]]

    Haha, getting too old, can't see, can't read!

    I've seen similar "self-ejecting" behavior with some USB enclosures myself.

    Doesn't seem to be cable-related or power-supply-related.

    I'm thinking it might be glitches in the enclosure's controller chip or board, perhaps with "sleep issues" as well.
     
  10. sPaCePiR8 thread starter macrumors newbie

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    Feb 4, 2015
    #10
    Thanks - I guess it just hurts to shell out >£15/$20 for a short USB cable...
     
  11. dyt1983, Feb 9, 2015
    Last edited: Jun 1, 2015

    dyt1983 macrumors 65816

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    #11
    edit: To remove personally identifying info not relevant to the conversation.
     

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