iMac 24" C2D - ?

If Disk Warrior failed to mount the HD even when booting from an OSX or DW DVD .. then you're in the realms of a seriously sick HD.

The next options would be to REMOVE the HD from the iMac and try further diagnostics/repair or send to a data recovery professional.

Thank you for the comment. This computer is only 6 months old and I am surprised the HD fried so quickly. Yes, it is still under warranty but it doesn't help the user to get a new drive. We have various regulations sending HD out due to confidentiality etc. (medical information).

Thank you,
Hazra

At least the Mac is under warranty.

I'd recommend returning the Mac to Apple .. EXCEPT they will make no effort to recover data .. they'll spend 10 minutes to determine if the HD is faulty and if it is .. they'll just give you a new iMac.

Have you tried booting the iMac in Target Disk mode (it is in effect a Firewire Drive) and connecting it to another mac??  If this works you could at least clone the HD and try and recover data from it.

Here is what you need to do. Download DataRescue II to another Mac:  http://www.prosofteng.com/products/data_rescue.php

Connect the two Macs using a Firewire cable. Start the iMac while holding down the t key. This will start it in firewire target disk mode. Then use DataRescue from the second Mac to try to recover the data from the first Mac.

There is a free downloadable trial at the link above, so you can try it at no cost. The free trial will list the recoverable files and let you recover one file as a trial. Once you are satisfied it will work, you can pay for a serial number to unlock the full capabilites.

If DataRescue won't recover the files, nothing short of a professional data recovery service will. DataRescue is really very good. I know from personal experience.

Target Disk Mode:  http://support.apple.com/kb/HT1661

P.S. DataRescue will recover data even from disks that you can't mount.

Alternatively, if you don't have a second Mac, install OS X on the 500 Gig external and boot to it by booting while holding down the option key. Then download DataRescue II to the external and try to use it to recover data from the internal drive.

The latter (booting to the extenal drive) is probably the easier solution on second thought.

Thank strung for your comments. I have already tried with DataRescueII. I have a licensed version and tried it. Installed it on the external drive, booted from the external drive and ran DataRescueII. But it did not show this HD so I could select it for recovery.  

I see that you mention that it rescues data from unmountable disk. Can you explain it a little more. How would I choose the disk to recover when it doesn't even show up.

Thanks for all your comments once again.

Thank you eoinosullivan. Yes, I have tried target disk mode as well. Doesn't mount the HD at all

ahadee .. if it doesn't mount at all .. you're in deep doo-doo .. removing the drive is pretty much the last option before sending it back to Apple.

In all my years using Apple products I've had 2 mac which had HDs that failed inside warranty .. I guess some HDs no matter whether they're seagate, WD, maxtor etc .. will have a certain failure rate and you can be lucky or unlucky.

If data rescue won't see the drive, I would assume it is toast. My recollection is that Data Rescue can see an unmounted drive in the same manner that Disk Utility does.

Thank you strung. I will use smartreporter. it seems like a useful app to have

ahadee - In a case where several Experts contribute to the question and provide assistance / answers it is good practice to split the points among all those who assisted .. rather than giving all the points to just the last answer.  

In this way more experts are encouraged to assist and provide advice in future.

Thank you