I've been having some horrible noises coming from my 27inch imac lately, and last week it failed to boot on me, and just this weekend I got an email from Apple
http://www.tuaw.com/2012/10/20/hard-...-of-1tb-imacs/
You can check if your HD is cleared for replacement here.
http://www.apple.com/support/imac-ha...0-192397&sr=em
Happy to get this email... fucking grinding sound has been driving me nuts.
Just thought I'd share this here.

