According to http://support.apple.com/kb/HT4904, my Mac should be able to update a firmware allowing me to run a diagnostic test on my computer; however, when I try to download the update, it says "this update is not supported on this computer". Why?
I need to run a diagnostic test on my early 2011 Mac because it reads "error code-50" every time I try to copy/back-up anything to all THREE of my NEW external hard drives. Please help. How can I check to see if the issue is within my computer and NOT 3 different "defective" external hard drives?
MacBook Pro, OS X Mountain Lion (10.8.2), This issue has become a nuisance.