External drive wont mount

Discussion in 'Mac Basics and Help' started by sierra722, Jun 9, 2013.

  1. sierra722 macrumors newbie

    May 8, 2011
    I have an external drive that I bought from other world computing about a year ago. I use it regularly, but rarely connect it to anything other than my MacBook Pro. Yesterday when I connected it I got the error "The disk you inserted was not readable by this computer". So I ran disk utility and found a few errors. Then I was able to repair the disk, but it wont mount within finder. When I try to mount it within disk utility i get "Mount failed". I have rebooted several times and reset the PRAM also. What would be the next troubleshooting step to mount or recover this drive?

    2.16 GHZ MacBook Pro running Mac OS 10.6.8

    Hard drive is Hitachi

    Manufacturer: Other World Computing
    Model: 0x0
    GUID: 0x1D202E0E30975
    Maximum Speed: Up to 800 Mb/sec
    Connection Speed: Up to 800 Mb/sec
    OEM ATA Device 00 Unit:
    Unit Software Version: 0x10483
    Unit Spec ID: 0x609E
    Firmware Revision: 0x301
    Product Revision Level: 0
    OEM ATA Device 00 SBP-LUN:
    Capacity: 500.11 GB (500,107,862,016 bytes)
    Removable Media: Yes
    BSD Name: disk1
    Partition Map Type: GPT (GUID Partition Table)
    S.M.A.R.T. status: Not Supported
    Capacity: 209.7 MB (209,715,200 bytes)
    Writable: Yes
    BSD Name: disk1s1
    Capacity: 499.76 GB (499,763,888,128 bytes)
    Writable: Yes
    File System: Journaled HFS+
    BSD Name: disk1s2
  2. Ichkamo macrumors member


    Jun 13, 2013
    World Wide Web
    Erase it and reformat it, if it doesn't work, I'm sorry to say that your HD may be dead.
  3. Fishrrman macrumors G5


    Feb 20, 2009
    "What would be the next troubleshooting step to mount or recover this drive?"

    Here's what I did when I was in a situation similar to yours. I had a drive with a partition on it that would no longer mount. Unfortunately, that partition had the data that I wanted on it (many hundreds of mp3 files).

    Even data recovery software (I was using Data Rescue) couldn't "touch" it, because it wouldn't mount and DR couldn't access the unmounted partition.

    My solution:
    1. I first re-initialized the drive into a SINGLE partition (but I -DID NOT- choose to "zero out" the drive)
    2. The drive was now "mountable" -- even though it showed that "nothing" was on it, no contents!
    3. I then launched Data Rescue and "attacked" the (so called) empty drive. DR "ignored" the drive's [new] directory and went "right to the platters" -- and FOUND the old file data which was still there (because I didn't zero out the data, remember?). It then scavenged the data from the drive sectors and re-assembled it and saved it onto a second "scratch drive".

    This scenario -MIGHT- work for you if nothing else does. No promises. But before you give up on the drive, it could help you get some of the data back.

    What you will need:
    1. A SECOND drive -- yes, you'll have to buy another one. I recommend that you get a USB3/SATA "docking station" and a "bare drive", instead of a pre-assembled external.
    2. Data recovery software, such as "Data Rescue 3" or "Stellar Phoenix Data Recovery".

    It will take some time, some money, and an effort to learn on your part. There is no way around this.

    Also, be aware that even when data recovery is successful (as it was for me), you will probably lose most (if not all) of your file names, and you will also lose any pre-existing folder hierarchies. These were "constructs of the directory", and to get at the data, it was necessary to replace the old directory with a "fresh" one (when you re-initialize).

    DO NOT DO NOT DO NOT "zero out" when you re-initialize! This WILL "wipe out" any chance of getting the data back!

    One other thing to be aware of: if your drive has experience an actual hardware failure, such as broken drive heads, the above process won't work. It's only for when the directory structures have been damaged (soft failure). When a drive has a hardware failure, it usually has to be taken apart before there can be any recovery -- an expensive operation.
  4. phoenixsan macrumors 65816


    Oct 19, 2012

    for Fishrrman and the procedure outlined. I use some like that with a problematic SD card damaged by a stupid PC. But I used Stellar Phoenix, Mac edition.

    I was able to recover all the info. But takes a lot of time (and was a 16 GB SD card, pal...!)

    So, give it a try if the info is valuable for you. Otherwise, think about the HDD as dead....:(


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