iMac - external hard drive not showing up

Discuss about computers & Internet. Including mobile phones, home appliances & other gadgets. Read about Windows security risks or virus updates.
Post Reply
User avatar
Posts: 6
Joined: Tue, 06 Jan 2009 6:01 pm

iMac - external hard drive not showing up

Post by dpankar » Fri, 13 Feb 2009 9:54 am


I have taken my Westernal Digital 250 GB hard drive from my old iMac and turned it into an external hard drive (with an A.C. Ryan SATA casing with Firewire connect) for my new 20" 2.4 GHz iMac.

However, it is not showing up mounted on my desktop or anywhere else. Have tried both Firewire and USB connections. (This external hard drive comes with its own power cable that I have connected.)

Please help.


P.S. My old iMac is busted, so can't go for the Target Firewire Computer mode.

User avatar
Posts: 405
Joined: Sat, 10 Mar 2007 9:41 pm
Location: Closer than you think

Post by ukdesigner » Fri, 13 Feb 2009 12:50 pm

when you say your old imac is busted, what do you mean?

Does it boot up but the screen doesn't work?

When the hard drive is in the new casing does it whir up?

Could be several things really.
1. Computer doesn't recognise the hard drive because it's busted/corrupted
2. Faulty casing and power supply
3. Faulty usb and/or firewire cable
Don't p*ss me off! I am running out of places to hide the bodies.

Posts: 91
Joined: Thu, 27 Nov 2008 10:14 pm

Post by rattlesnake » Sat, 14 Feb 2009 12:58 pm

As this is your second Mac I will assume you are pretty well versed with them.

Try booting into single user mode or open up a shell window. Enter fdisk -l at the command prompt. If drive not there it is not being picked up by the kernel so it is likely a hardware issue.

Drives that don't get picked up either have a hardware issue i.e computer doesn't see drive (fdisk) or a filesystem issue i.e. computer sees drive but does not mount it (filesystem incompatibility / driver issue).

Test it on another computer - if Windows note it may not be seen in OS but device manager should pick up the disk.

The Alchemist
Posts: 2
Joined: Thu, 26 Mar 2009 10:23 am

Post by The Alchemist » Thu, 26 Mar 2009 10:40 am

I had similar problem with my macmini last year.....yet it worked perfectly when connected to a Windows based machine. After a lot of research on Mac dedicated forums, it turned out to be a compatibility issue with the chipset used in the HD case I had used. Apparently there are 2-3 different types and not all work with mac platform.

So, as first step, try it out on a windows machine (a friend's if you don't have one). You may therefore need to consider a different casing and ask them to confirm it's compatible with Mac platform.

Hope this helps

Posts: 5
Joined: Tue, 24 Mar 2009 2:20 am

Post by Henry_21 » Sun, 29 Mar 2009 7:03 am


If u have password on ur Westernal Digital on windows...then u need to removed passoword...maybe thats the reason y ur external hard driver not showing on mac screen.

Posts: 1
Joined: Wed, 20 May 2009 1:12 pm

Post by janebush08 » Wed, 20 May 2009 1:15 pm

Hi dpankar, check out following resource that may help you to find solution: ... found.html

Posts: 1
Joined: Mon, 25 May 2009 1:16 am
Location: Singapore

Post by death_cheater » Mon, 25 May 2009 1:25 am

I would suggest first go in system profiler and look under the section if it is even detecting any information on the fire wire or usb bus ...if yes then seems to be more like a os recog issue which can be sorted out

Post Reply
  • Similar Topics
    Last post

Return to “Computer, Internet, Phone & Electronics”

Who is online

Users browsing this forum: No registered users and 0 guests