6 Replies Latest reply: Sep 18, 2013 11:58 AM by cyndielouwho
TKrupp Level 1 Level 1 (0 points)

I just got my new 27" 3.4ghz i7 iMac today, and I've been trying to transfer everything over from my PC VIA external hardrive; however, my iMac is not showing that an external HD is connected.  I initially tried connecting 2 USB powered external drives into all 4 USB ports with no luck.  The third external hardrive I tried is powered by an AC adapter, and that was recognized by only USB ports 3 and 4, ports 1 and 2 did not recognize it.


Could there be a problem with my USB ports?  Seeing as only ports 3 and 4 picked up the AC powered hardrive, and none picked up the USB powered external drives.  All the USB ports, however, work with my iPhone, etc.


I have the options ticked in Finder preferences to show Hard Disks and External Disks on the Desktop.  I also looked in the Disk Utility and the only external drive that showed up was the AC powered drive plugged in ports 3 and 4.

iMac (27-inch, Late 2012), OS X Mountain Lion (10.8.3)
  • Eric Ross Level 6 Level 6 (11,665 points)

    Are you using Migration Assistant to transfer your data?  If so then take a look at this link, http://support.apple.com/kb/HT1408


    Try launching disk utility and see if the drives show up, I am thinking the drive is formatted NTFS,

  • TKrupp Level 1 Level 1 (0 points)

    No, I'm not using Migration Assistant. 


    All of the drives I tried using are currently formatted NTFS which Mac's can read but not write to which is fine because I'm only transferring data to my Mac from my old PC.  The only drive that my iMac recognized is the external drive that is powered by a USB adapter, and only in USB ports 3 and 4, not 1 and 2.  The other USB powered external drives I tried were not recognized at all in any USB ports.

  • TKrupp Level 1 Level 1 (0 points)

    So, I have a few updates to this problem.


    I just got my new Macbook Pro (non Retina) today in addition to the iMac I got last week, and it also has the same problem of not recognizing or mounting either of my bus powered external Hard drives.


    I spoke to several people when I called Apple Care and nobody was able to help me or explain what the problem could be, so I'm returning my iMac for an exhange. 


    On a hunch I decided to call the manufacturer of my ioSafe Rugged Portable, and they were more helpful than Apple.  They stated right away that Apple uses a high/low power setting for their USB ports, and because of their proprietary USB technology, certain third party devices such as external hard drives are not provided enough power for them to run properly.  Of course when I told the Apple Care Senior Advisor that I was speaking to this information, he rudely flat out denied that this was the case.


    I'm a mobile DJ and I rely heavily on external hard drives for my huge music library, so I'm ripping my hair out right now.  For an iMac, and Macbook Pro that I paid almost $3,000 EACH for, they should absolutely be able to handle such a simple task as being able to power and mount an external hard drive.  

  • cyndielouwho Level 1 Level 1 (10 points)

    I had the same problem. I emailed ioSafe and they called me back. The new macs have a power saving chip so the ioSafe is drawing to much power. You will need to plug in both usb ends on the y cable it came with  into both usb ports on your mac. You can send ioSafe your address and they will send you the new cable for use with the new macs. I hope this helps it took me 5 hours to figure it out!

  • TKrupp Level 1 Level 1 (0 points)

    Thank you!  Yes, I did end up getting the new USB cable from ioSafe, and now it works perfectly which was a huge relief.

  • cyndielouwho Level 1 Level 1 (10 points)

    Sorry this took so long for me to see. That's great! Glad you got your cable!!