External Hard Drive not showing in Disk Ultility

Discussion in 'iMac' started by buwnkle, Apr 6, 2018.

  1. buwnkle macrumors newbie

    Jun 18, 2009

    I have an external hard drive that use to show up on my iMac (2017 High Sierra), but it has stop showing up. It lights up and I can feel that its on so I know its working.

    Below are the steps I took to fix it:
    • I tried different usb ports put it doesn't show up.
    • I plugged in my spare WB MyBook drive to see if the USB ports are working, my WB hard drive shows up perfectly fine.
    • I've switch the cables, still doesn't show up.
    • Connect the hard drive to a PC, shows up.
    • Connected the hard drive to an old MacBook and it shows up!
    I'm completely lost! Why did it stop showing up on my iMac 2017?


    ps. When I look in Disk Utility I do not see the hard drive.
  2. Fishrrman macrumors P6


    Feb 20, 2009
    Could be..
    - failed drive hardware
    - failed drive controller board
    - failed connection (to USB connection)

    Sometimes drives just quit on you.
    That's why I generally don't trust either Seagate or WD drives... (sigh)
  3. buwnkle thread starter macrumors newbie

    Jun 18, 2009

    But it works on other computers perfectly fine....
  4. Fishrrman macrumors P6


    Feb 20, 2009
    "But it works on other computers perfectly fine...."

    Hmmm... something I overlooked earlier.
    What -format- is the drive?
    That could make the difference...

    If nothing else works, I suggest you re-initialize it (on the PC) to exFAT.
    See if that works on the Mac side.

    My general recommendation is:
    - For a drive that you're going to use with the Mac to keep important files on, format it to MAC FORMAT: Mac OS extended with journaling enabled.

    - For transferring things between a Mac and a Windows PC, use a drive just for this purpose that is "cross-formatted" (non-Mac format). A USB flashdrive of sufficient capacity works fine for this.
  5. buwnkle thread starter macrumors newbie

    Jun 18, 2009

    it’s formatted to FAT32.

    I plugged it in a Mac and PC and it’s formatted to FAT32. Is that cross-formatted?
  6. Fishrrman macrumors P6


    Feb 20, 2009
    Not sure what else to tell you.
    You seem to have "covered most of the bases".

    At some point -- if one has an individual piece of hardware that is a source of problems with one computer, but works with others -- you just have to throw in the towel, and use the drive with the computer that it "works with", and stop using it with the one it WON'T WORK with.

    Have you tried all the ports on the iMac? (one port might be "weak")
    Does the iMac work with all your OTHER drives?

    If this one just won't work with the iMac anymore, I'd put it to other uses, and stop worrying about it.
  7. buwnkle thread starter macrumors newbie

    Jun 18, 2009

    Thanks for the input. But using the other iMac is not an option. as it is a 10yr old imac.:(
  8. NoBoMac macrumors 68000

    Jul 1, 2014
    Could be something akin to this. On my MBP, one of the USB ports has some "wobble" to it, especially with a couple of drives and their cables. Other USB port, no problem.

    OP: have you tried to access any of the files on any of the machines that can see the drive? Wondering if they are mounting but are messed up in some way. And: what do you see when you run the command "diskutil list"?
  9. buwnkle thread starter macrumors newbie

    Jun 18, 2009
    I’ve never ran the diskutil list command before. How would I do that?

    As far as the files, i’m not getting any errors when I open them on other computers. I also tried the external hard drive in all of my usb ports.
  10. NoBoMac macrumors 68000

    Jul 1, 2014
    All you need to do is bring up Terminal.app (Applications > Utilities > Terminal) and type in, minus the quotes "diskutil list", and then hit the enter/return key.

    It's basically a Disk Utility minus the GUI and more options.
  11. buwnkle thread starter macrumors newbie

    Jun 18, 2009

    This what I get when I did that.

    Attached Files:

  12. nambuccaheadsau macrumors 68000


    Oct 19, 2007
    Nambucca Heads Australia
    Was the above undertaken with the external connected and powered on?
  13. bopajuice, Apr 8, 2018
    Last edited: Apr 9, 2018

    bopajuice Suspended


    Mar 22, 2016
    Dark side of the moon
    Personally I think it is a controller issue.

    I have had SD cards that stopped showing up on a laptop for no reason. I changed nothing. An external drive that would no longer show up when plug into a USB port. I had an action cam that stopped mounting on the desktop altogether on any computer. On one computer it was happening with just one port, but then it started on the other.

    Could be software related. Have you tried disk utility? Reseting Pram, and all the other reset stuff?

    Other than that I had to live with it. I've had external drives that I could not format on one laptop. Tried formatting it in another computer, it worked fine and showed up. Reformatted the drive on the second computer, brought it back to the original one that did not see it, reformatted the HD again and it worked fine.
  14. NoBoMac macrumors 68000

    Jul 1, 2014

    Or, VERY remote chance, the USB ports are not putting out enough juice and or the drive is pulling more than the Mac ports can deliver. Ala in the old days of needing to be sensitive to the order you plug things in to the computer to let the big power drawer get dibs then everyone else.
  15. buwnkle thread starter macrumors newbie

    Jun 18, 2009

    I’m a newbie to this so when you say it’s a controller issue what does that mean? I have not tried resetting the Pram. How do I do that?
  16. NoBoMac macrumors 68000

    Jul 1, 2014
    PRAM reset: https://support.apple.com/en-us/HT204063

    Re: controller chip: simply put, there is a circuit/chip in the disk drive that facilitates communication between the computer and the disk drive. The controller might be flaky, a bug, failing, etc.
  17. buwnkle thread starter macrumors newbie

    Jun 18, 2009

    The PRAM reset didn't work. I'm going to try and reformat the drive and see if that works.
  18. ignatius345, Apr 10, 2018
    Last edited: Apr 10, 2018

    ignatius345 macrumors 68000

    Aug 20, 2015
    Drives definitely sometimes just quit on you (it's only a matter of time) but I can't count how many "X brand drives are more failure-prone!" comments I've seen, where X = any major brand. Everybody seems to have their favorites or no-go brands but I personally buy indiscriminately from whichever recognizable brand is on sale, and really have never had any more trouble from any more than another.

    For the last 10 years or so I've had a setup where my iTunes media is on an external drive and there's another big desktop drive running Time Machine to back up the Media drive and the internal drive. I also generally have a few portable drives on hand which I use for monthly backups which are kept offsite. I've gone through a lot of drives, but almost always because I need more capacity, not because of failure. (I guess maybe if I kept my drives around more than a few years, I'd be on the right-hand side of that "bathtub"-shaped failure graph that's apparently so common.)

    Right now I've got a 3TB Seagate and I think a 5TB Toshiba on my desk and they've been running just fine for I think going on 2 years. I've had quite a few WDs -- those basic Elements ones for desktop and the Passport series for mobile -- and I think one desktop WD drive died. I think I had a bit of enclosure trouble with a LaCie, but those are so overpriced I don't even consider them.

    But yeah, you have to regard every storage device with suspicion and assume it could fail at any moment. Nothing important should ever exist on only a single drive.

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