help with unreadable external hard drive

I am having problems with an external hard drive and found your Email in yahoo answers.

I have a 'MB' external hard drive with a Mac OS X 4 11. A few days ago I turned off the Mac at the back button, after the screen went dark, I unplugged the HD only to find the Mac came on again. The Mac must have been in sleep mode? Since this time the Mac will not recognise the HD.

I tried another USB, making sure the preferences under finder is checked for all items and tried data recovery, PRAM reset, Disc Utility, which did see the drive (in gray) and it gave me this message; Error; underlying task reported failure on exit / 1 non HFS volume checked / 1 volume could not be repaired because of an error / unable to read FAT (input/output error).

I am hoping I can still use this external HD or could there be bad news ahead? I have not yet tried this on another Mac. Please can anyone help or advise? Thank you.

Mac OS X (10.4.11)

Posted on Mar 29, 2011 9:21 PM

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8 replies

Mar 29, 2011 11:09 PM in response to ikce wicasa

It is Mac compatible in that Macs can kind of use FAT formatted drives, and the drive can be reformatted to HFS for Mac use. FAT is not the best format to use with Macs since it is only partly supported. Macs come with disk Utility which can try to repair a drive, but not if it is FAT. For FAT repair you have to try a PC.

Unfortunately, unplugging the drive while it was still active probable corrupted the file directory since it was not shut down properly. This may be exacerbated by the unplugging also completely abruptly powering down the drive. In general it is best to use self-powered drive with Mac laptops since they are kind of marginal in being able to supply adequate power. Sight power fluctuations can also corrupt drives.

Mar 30, 2011 11:33 AM in response to ikce wicasa

that was my backup!

If you truly mean a backup then that means you still have the original files on your internal drive, or wherever. You just make another backup. If you mean it was an archive/overflow drive then that's not a backup (and you should start thinking about buying another HD to save both the files on your internal and external since either of those could fail without warning).

So are you suggesting I go to a place/individual that does PC data retrieval? And does this mean I buy another external HD?

I don't know much about file recovery on PCs. If this was a Mac drive then there would be a good chance you could either use Disk Utility on your Mac already to repair it, or perhaps a utility such as Diskwarrior ($100) to do the same. That repair could be done pretty much in-place. It's only when a drive is really seriously damaged, in particularly physically, that you need a second HD. Again, this is if you could do this on a Mac.

There are supposedly Mac based recovery tools that can also recover FAT, but those would likely need a second drive and the results might not be pretty (files, everywhere, maybe without original file names).

I'd find a buddy with a PC and see if they have something on there that can do it for a cup of coffee. 🙂

Mar 31, 2011 6:23 PM in response to BDAqua

thanks for your help guys, I have now taken it to a professional place to see what they can do.

I took this HD to a friend with a PC to see if would be recognized, it asked 'do you want to re format this HD'?..which means erase..why don't they use understandable English? This friend clicked OK without asking me until I asked him to stop. Lesson; get at least 2 back ups!

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help with unreadable external hard drive

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