8 Replies Latest reply: Jun 13, 2008 3:29 AM by runermeister
Paul Hiscock Level 1 Level 1
My USB/firewire external hard disk was accidently disconnected while mounted and now it will no longer mount. Disk Utilities doesn't see it nor does Disk Warrior. I've tried USB and Firewire and booted up the MAC while it was switched on, but with no success. Any suggestions?

G5, Mac OS X (10.4.11)
  • Jeff Kelleher Level 4 Level 4
    None that you're going to want to hear...I think you've figured out the problem already.
  • a brody Level 9 Level 9
    Classic Mac OS
    If the G5 is 4 years or older, try replacing the clock battery.
    If the G5 is younger, try zapping the PRAM:

    If neither helps, and there is data you must retrieve from it get a second hard drive for your G5 at least as big as the external and Prosoft Data Rescue and/or Subrosasoft Filesalvage and see if either is able to recover data from it. If neither can, only an expensive data recovery company such as http://www.drivesavers.com/ may be able to repair it.
  • Limnos Level 9 Level 9
    Have you tried switching computer ports? Maybe a port got fried.
  • mac user64 Level 1 Level 1
    The exact same thing has happened to me. Any other suggestions out there are most appreciative!

    My external firewire hard drive does not mount. It is "greyed out" in the disk utility, and disk utility will not repair it.

    If at all possible is there way to retrieve the data?
  • cornelius Level 6 Level 6

    I suspect that you have gone through the usual trouble shooting list:
    • try different ports
    • try different cables
    • shut down computer and external HDD
    • disconnect external HDD from computer
    • reconnect and reboot

    If after all this there is still no action
    • is the formatted volume damaged?
    • is the drive mechanism itself damaged?
    • could it be the firewire bridge?
    • could it be the power supply on the drive that is damaged?

    If it is the formatted volume, the HDD should show up in DU, or you should get a message that the disk is not in a recognizable format do you want to initialize.

    If it is the drive mechanism itself, you will not feel or hear the drive running (this is also true if there is no power).

    If it is the firewire bridge, the drive may be running but it is not communicating with the computer.

    If it is the power supply, you can test it with a simple tester.

    My guess is that it is the firewire bridge. My experience is that this is the most vulnerable element in an external HDD. To test this, remove the drive from the present enclosure and place it in another enclosure.

    There are verly likely things that are not accounted for in my list, and there are doubtless things you may have experienced of which I am not aware. However, these are some questions to ask as you seek to unravel this puzzle.

    Good luck.

  • Texas Mac Man Level 8 Level 8
    What to do if your computer won't recognize a FireWire device

    Dealing with FireWire problems (drives not mounting, devices unrecognized, etc.)

    Common fixes for USB device issues (unrecognized, etc.)

     Cheers, Tom
  • Ira Miles Level 1 Level 1
    When you run disk utility does it take a long time to "gather disk information"? If so, during the process turn your external drive off and on. The volume should show up but probably won't mount. Highlight the volume with the name you gave it (subvolume or whatever you want to call it) and run disk verify. It should mount.
    it's so crazy it just might work.
  • runermeister Level 1 Level 1
    Same situation here,

    Twice I have burned a large iDVD file from an external firewire drive. Afterwards, the icon for the drive will disappear from the desktop. Disk Utility can see the drive, but cannot mount it. It will scan fine, but does so quickly, as if no data is there. Since the drive is only for storing TVR files before burning, nothing serious is there, so I reformatted, and bingo, all is well.

    The same thing happened the very next time I burned a 10g DV TVR file. BTW, the external burner is a formac. Ideas?