I'm mid way through replacing the hard drive in my MacBook Pro (mid-2009). I've created a boot disk (10.8) on a SD card which I am booting from.

On trying to format the new drive with disk utility (in from the installer) I am being presented with the following error.

Disk Erase Failed
Disk Erase failed with the error:
Unable to write to the last block of the device

Googling suggests this error message is somewhat ambiguous. The drive is brand new and from disk utility the SMART status is "verified".

Thanks in advance


The solution was really rather simple. A dead HD cable causing the HD to show up (and verify) but not function.

  • I am having the same issue, any advice?
    – lomse
    Oct 8 '14 at 12:10
  • 1
    In my case it was the cable. If your problem is being caused by a dodgy cable you will need to replace it. On my model you aught to be able to replace the cable without taking anything out. Just open up the back, using a plastic tool prise the cable end off of the logic board, the other end (the bit which attaches to the hard drive) can then be removed.
    – osnoz
    Oct 9 '14 at 16:55
  • 1
    If you cannot get at the hard drive end or if the cable goes under the hard drive or its assembly you will need to remove the drive itself. This in my case required a tourq 5 screwdriver (cheep on ebay). When buying the new cable be cautious of cheep imitation cables on ebay, I was advised to bite the bullet and slash out on a genuine part.I cannot guarantee that your problem is definitely caused by a dodgy cable, you could have a duff hard drive on your hands. If you have the ability to test that hard drive with another computer do try it out.
    – osnoz
    Oct 9 '14 at 16:57

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