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Can't See External Hard Drive

Hi,

At one point, I had 4 external hard drives plugged into my IMAC and I could see all of them. For some reason, now, I can't see one of the drives that is plugged directly into the back of my IMAC (USB Port), but I can see one of the external drives that is plugged into a USB hub... But no others...???? I have checked plugs, power, etc... I haven't made any major changes. Can anyone help?

Thanks!

MacBook Pro, Mac OS X (10.6.8)

Posted on Feb 18, 2012 7:59 AM

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Posted on Feb 18, 2012 12:57 PM

open finder go to prefences>general, see if the HD and external drives are checked. If they are checked uncheck them, close the finder then reopen and check them again.

Try ejecting the drives and reinstalling them.

16 replies

Feb 18, 2012 1:29 PM in response to Leejg

Where aren't you seeing them? Do you see the drives in Disk Utility?


Try a PRAM Reset:


At the startup chime, hold down Option-CMD-P-R together, listen for two more chimes, total three, then let go to finish booting.


Is the hub a powered USB hub? Is the one drive that is being recognized the only drive plugged into that hub?


Are any of these by chance WD Externals?


While you're at it, try an SMC Reset:


Shutdown, unplug from wall power, leave ten minutes, hold in power button for five seconds, connect back to power and startup again.


Message was edited by: WZZZ

Feb 20, 2012 5:05 PM in response to WZZZ

Hi Wzzz,

Thanks so much! I was able to see all of them in the Disk Utility. I 'remounted' all of them, and it worked fine except for 2 of them. A repair in the disk utility worked for one of them. I was then able to remount it and it works fine. The other one the disk utility coudn't repair. It says there is a problem... I don't understand how all of these were 'unmounted' and why 2 had a problem...


By the way, it is a powered USB hub but the one in particular that I wanted was plugged directly into the back of my IMac! ALL of the other disks were plugged into the USB Hub. The disks in question are all Seagate Externals. Is that significant?


The most important one is working again, but I am worried that I have no idea why this happened. Thanks so much for your suggestion of the disk utility. If I can't fix the last one, I may try your final suggestion.


Thank you, thank you for your help!

Feb 20, 2012 5:11 PM in response to Leejg

For diagnostic purposes try each drive individually as opposed to daisy chaining them. Plug them, one by one, into the back of your computer. See if you can mount each that way, or have disk utility repair them. If the disk can't be mounted when it's the only one and DU can't see it then either the external enclosure has a problem or the disk needs replacing.

Mar 10, 2012 12:27 PM in response to WZZZ

I have this same problem and yes my drive is the WD My Book Studio and has all of my iTunes media on it. 😢

Any help would be appreciated. I have already ordered the upgrade version of Disk Warrior and waiting for it to come. What can I do. Also on the day it went out I updated iTunes and accidently knocked out the plug, so it ejected wrong.

Mar 10, 2012 12:42 PM in response to MaGrzly

I don't know if this is the solution for your particular issue, but a friend had one of those that conked out. I took out the drive itself, which was still fine, and put it in a decent enclosure -- the WD enclosures are crap -- and it was OK. It's not hard to do.


You want one of these. I'd jump on it, that's a great price. Note: it's FW 400, so you might need a 9-6 pin adaptor or cable, depending on the FW port on your Mac.


http://eshop.macsales.com/item/OWC/MEFW934FWU2K/


Or this one, if you want 400/800.


http://eshop.macsales.com/item/OWC/MEP944FW8EU2/


Once you get the drive out of the WD, it takes twenty minutes or less to install. Only a screwdriver needed.

Mar 11, 2012 6:21 PM in response to MaGrzly

It's not difficult. You just have to work slowly and carefully. It mostly involves prying the plastic case apart. Then, when you're inside you need a small Phillips screwdriver to remove the drive from the mount and then unplug the connectors -- screwdriver not needed for that, but maybe a slimmed down chopstick or popsicle stick to act as spudger (small pry bar) if the connector is hard to remove. Wiggle it out gently and don't pull from the cable. To put it in the OWC case, you really just need to open that and slide the WD drive right in. No connectors to fuss with.


There's this one, but it may not fit exactly with yours.

http://www.instructables.com/id/Disassembling-a-Western-Digital-My-Book/


If you do a search "open disassemble wd my book external, " you'll get a number of hits, including some YouTube videos. The My Books aren't all the same, so there will be some variations. Just make sure you first discharge any static electricity buildup on your body on a radiator or something similar and try not to directly touch any of the contacts or the printed circuit underneath. Hold the drive by its edges.

Can't See External Hard Drive

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