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Not recognizing external hard drive

I have a 1 terabyte seagate external hard drive that I used to back up my PCs and tried to connect it to my Macbook Pro to transfer the files over from my old computers, but the Mac won't recognize the external hard drive at all. Any suggestions?

Macbook Pro 15" 2.66 ghz, Mac OS X (10.6.4)

Posted on Sep 5, 2010 1:58 PM

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Posted on Mar 9, 2011 7:41 PM

I am having the SAME problem User uploaded file Why is Apple not doing anything about this? I have a lovely LaCie, and I simply cannot get Timescape to recognize it. If someone calls Apple Care, can they please post the solution? (my applecare has expired)

Thanks!
187 replies

Sep 6, 2010 2:15 AM in response to Weeblerock

Weeblerock wrote:
It wasn't being recognized in Finder or in System Profile.


Hi Weeblerock,

Are you sure it's not being recognized in System Profiler? Because that's a whole other bag of issues. By System Profiler I'm referring if you go Apple Logo > About This Mac > More Info and then select the bus that the drive is connected via to your computer. Which is most likely USB.

Disk Utility, an application within the Utilities folder is something completely different. If it sees it there and it's not a mount point then it's an NTFS / OS X file format issue. Macs can read from NTFS volumes but I'm not aware of a method to write to an NTFS volume.

Sep 6, 2010 4:57 PM in response to Weeblerock

Hi Weeblerock,

That's interesting. The fact that it's not seeing the drive even in System Profiler is not a good sign, as the drive isn't even being seen at the bus (I/O) level. Is it a bus powered drive or does it draw power from the wall as well?

The fact that the drive isn't even being seen via System Profiler tells me that it's not a partition/formatting issue but more of a hardware compatibility issue. Any other external HDs to test against?

Sep 21, 2010 5:50 PM in response to Weeblerock

Jumping into this thread to say I've run into the same problem--my WD Elements 1TB drive works fine on Windows computers (I've tried a few), but my Macbook Pro won't even pick it up at the I/O level. I'd reformat the drive if I could only get my Mac to recognize that the darn thing exists, heh. Any suggestions appreciated...

Oct 14, 2010 5:49 AM in response to Ganamex

I have the same problem. I have been using an external hard drive for a few months now and all of a sudden my Macbook has stopped recognizing the drive when I plug it in as I always correctly had done. It says TimeMachine is Delayed. My last back up was Oct 2, 2010. I have tried restarting my computer with the drive attached and with it not attached. Still does not recognize it. When I say recognize I mean it does not show up on the desktop and the time machine application cannot see any attached drives.
Any help is appreciated.
Thank you

Oct 17, 2010 4:57 AM in response to CbuscCycler

Just thought I let you know, i reformatted (deleted ) the drive sacrificing previous backups and immediately the drive was recognised by my system and the icon appeared on the desktop.
I believe that the last upgrade to the mac software is the culprit that made the drive disappear until reformatted.
It may be a price to pay to reformat but at least you get the drive back and can do a new backup.
Hope this helps
Co

Message was edited by: Co de Kleuver

Feb 2, 2011 8:41 PM in response to kreesetaylor

I am having this same problem. I have a USB external drive and a Firewire 800 drive that I was backing up to using Time Machine and suddenly Time Machine just froze up. Then when I restarted the machine just gave me a grey screen and wouldn't boot until I disconnected the drives.

Now the drives won't show up in the finder. I can see them attached using system profiler but I can't access them. This is really frustrating.

Anyone have any solutions?

Mar 2, 2011 10:10 AM in response to Weeblerock

I've been scouring forums trying to find a solution to this problem:

I am trying to restore files to my girlfriend's MacBook from her external hard drive. She had previously backed up files so I know that her WD2500ME is compatible with her machine. This external hard drive does not use a separate power source, but draws only from the USB cable. The drive is fine. I've plugged it into my PC and have been able to view her files. The file system is FAT32 which should be fine with her mac. When plugged into her machine, the HD lights and spins up. It does not show on her desktop, in the Finder, or under Disk Utility. As far as her MacBook knows, nothing is connected. I have reset PRAM, but didn't change anything. I've encountered one more curious variable. I have two USB cables that I've tried connecting the HD with. The first allows the drive to light and spin up on both of our machines, but neither will recognize it. The second cable allows full functionality with my PC but when plugged into her MacBook the HD only lights (and blinks) but does not spin up. I'm thinking we're looking at some sort of cable issue here, but I'm baffled as to why these two cables are behaving in such different ways. Any new suggestions would be greatly appreciated.

Not recognizing external hard drive

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