Hi all I need to replace the HDD in my iMac 27 inch. The HDD is the one with the Temp sensors built-in to the HDD. I need a model number before I take my iMac apart. Can anyone help with a model number? I would appreciate it. The iMac model is A1312. BTW, I know I should look at about this Mac, but the system info would not load even booting from my MacBook in target disk mode. Thanks in advance.