Apple has determined that some iMacs bought between October 2009 and June 2011 have a defective Seagate hard disk. Those iMacs have got, generally, a ST3100528ASQ hard disk. Only 0,2% of iMacs are affected, but you should take it to prevent future issues with the Mac.
As the replacement will erase all your data, you should follow some steps before taking your computer to the Apple Retail Store.
1. Determine if your Mac is elegible
All the iMac owners with one of the hard disks damaged are receiving an email from Apple, but if you didn't receive it and you're worried, just go to this website > http://www.apple.com/support/imac-harddrive
It will ask for the serial number. To see the serial number of your computer, open > About this Mac and press Version twice, so the serial number will show.
2. Make a backup of all your data
After you know that your Mac is affected, you must make a backup of all your data. If you don't have an external disk, you have to buy one; you can buy the external disk you want, but I recommend a FireWire or Thunderbolt disk because they're way faster than a USB disk.
Instead of the normal Time Machine backup, you should make a clone of the hard disk. That's because Apple will give you a blank hard disk or installed with another Mac OS X edition.
3. Erase the hard drive
You can avoid this step, but I recommend it because Apple will take the hard disk. It depends of what OS X version you use.
- Mac OS X Snow Leopard
For Mac OS X Snow Leopard, you have to boot from the Mac OS X Install Disc pressing C key when your Mac starts. Then, go to Utilities > Disk Utility, select your hard disk in the sidebar, go to Erase tab and erase the disk.
- OS X Mountain Lion and Lion
If you have Mountain Lion or Lion:
- Press Command and R keys when your Mac starts.
- Open Disk Utility, select Macintosh HD in the sidebar, go to Erase tab and erase the disk.
If you want to be more secure, you can use one of the Disk Utility security options in order to erase the disk. It will take more time, so be patient.
4. My Mac is ready to replace the hard drive. Where must I take my iMac?
After doing the clone, your iMac is ready. Apple gave you information about where to take your Mac. The most recommended place to take the computer is to an Apple Retail Store, so make an appointment > http://www.apple.com/retail/geniusbar/
Also, you can take your computer to a reseller, but it would take more time. On an Apple Store, the repair should take from 1 day to a week. When your hard drive has been replaced, don't forget to make an appointment to take it.
5. I have my Mac back to home. What can I do to restore the clone?
Now, you've taken your Mac back to home and you find that a) the hard disk is blank; b) it has got an OS X preinstalled. Follow these steps to restore the clone:
- Mac OS X Snow Leopard
- Insert the OS X DVD that came with the computer and press C key when your Mac starts.
- Go to Utilities > Disk Utility, select Macintosh HD in the sidebar and go to Restore tab.
- Drag the external disk to Destination box and select Restore.
- OS X Lion or Mountain Lion
- Press Command and R keys when your Mac starts and open Disk Utility on OS X Utilities window.
- Select Macintosh HD in the sidebar, go to Restore tab and drag your external disk to Destination box, and select Restore.
If the hard disk is blank:
- If you have Internet Recovery (OS X Lion and Mountain Lion)
Just do the same as with Lion or Mountain Lion installed, but pressing Command, Option and R keys.
- If you don't have it
If your computer doesn't support it, you have to reinstall Mac OS X Snow Leopard and upgrade to Mountain Lion or Lion, and finally, restore the clone.