Resolved Hard Drive Not Recognised After Upgrade

Discussion in 'iMac' started by element15, Jan 23, 2016.

  1. element15 macrumors newbie

    Jan 23, 2016
    Note: I am new to this forum. If this type of question is not appropriate for where it is posted, please accept my apologies and let me know where to go if you can. Thanks.

    Yesterday I decided to upgrade the hard drive in my 2011 21.5-inch iMac according to this guide. Since booting up after installing the new drive, my system is not recognising that there is a drive installed at all. Disk Utility doesn't show it, and it doesn't even appear in my /dev directory.

    I can still use the machine, as the OEM hard drive was/is not the drive on which OS X is installed. About a year ago, I installed an SSD according to this guide, and have used the OEM disk as storage. The only other hardware that has been changed is a RAM upgrade I installed shortly after purchasing the machine in 2011.

    The new hard drive is a WD Blue 4TB, which replaced the original WD Blue 500GB. It may also be worth noting that the hard drive is not even recognised when booting from an OS X recovery USB drive.

    I appreciate any help or insight, and if this particular problem has been solved in another thread, then I kindly ask that you point me in the right direction.

    Detailed specs for my machine are as follows:
    OS X 10.11.2
    iMac (21.5-inch, Mid 2011)
    Processor: 2.5 GHz Intel Core i5
    Memory: 12 GB 1333 MHz DDR3
    Startup Disk: SSD 224G
    Graphics: AMD Radeon HD 6750M 512 MB

    Edit: apparently one cannot use \[CODE\] formatting inline.
  2. maflynn Moderator


    Staff Member

    May 3, 2009
    Here's some basic checklist items to see if the issue is simple to fix or isolating what's wrong, i.e., cable, drive etc.

    Check the cabling, to make sure the cables are firmly set on the drive and logic board

    Do you hear drive spinning up when you power up the computer?

    Can you try the drive in an external enclosure or another computer?

    Try replacing the cables
  3. element15 thread starter macrumors newbie

    Jan 23, 2016
    I'll see if I can open it back up and check the data cable, but the drive is being powered. I cannot hear it spin up at boot (mostly because of the HDD fan), but I do hear the drive head park at shutdown. Also, since my original post, I booted into my Ubuntu partition and it does not see the drive either.

    I don't have a 3.5-inch enclosure or another desktop, but I do have a Seagate Backup Plus, which has an interchangeable base (this allows the drive to be upgraded from USB to Thunderbolt). This base works off of SATA, so there is potential there.

    One potential thought I had: Do drives still have 'settings' pins with a jumper? I know this was the case with older IDE drives. If so, could that have an effect?
  4. MadDane macrumors 6502a

    Apr 5, 2015
    It sounds like a bad connection. The best bet would be to open it up again and make sure all cables are firmly attached, like Maflynn suggested.
  5. MacRobert10 macrumors 6502

    Nov 24, 2012

    Two things:

    First, reset the NVRAM. The NVRAM stores information about the drives, and if a new drive is installed and it isn't updated, the drive very often isn't recognized. The following link tells how to reset the NVRAM:

    How to Reset NVRAM on your Mac - Apple Support

    Second, on the newer OS releases all drives greater than something like 2.2GB (I don't remember the exact number) are created as Core Storage, not HFS. I kind of doubt that's the problem but it may be.

    If it isn't either of them then maybe a hardware of installation problem is at fault.
  6. bogg macrumors 6502


    Apr 12, 2005
    Hfs+ is a filesystem, so even core storage devices gets formatted as that...
  7. maflynn Moderator


    Staff Member

    May 3, 2009
    I don't think its NVRAM because he doesn't see the drive at all, including Ubuntu which doesn't read the NVRAM
  8. element15 thread starter macrumors newbie

    Jan 23, 2016
    Alright, so the drive is working now.

    I took the iMac apart again, and upon doing so, the cables did not appear to be loose, so I removed the drive, and attached it to the Seagate base I mentioned earlier:

    Then I plugged it in to my MacBook. the drive appeared, albeit appearing as an uninitialised Seagate drive. At that point, I was almost sure it was the data cable, so I reassembled, hoping that I would not have to take it apart again to replace a SATA cable. (The cable attaches to the back of the logic board. I've had the logic board out before to install an SSD, and I never want to have to do that again.)

    Needless to say, I started up and it was working. No NVRAM reset necessary (although I did have to do this when installing the SSD a while back).

    Thank you all for your help, even though it turned out to be a dumb thing that I should have checked *before* posting.

Share This Page