Bad internal HD cable on mid-2010 Macbook Pro
The computer was experiencing intermittent freezes and finally became unusable. I had thought this was a hard disk problem, especially since there was an error in trying to reformat the drive. However, it turned out that the internal HD cable was bad. The disk would format from an external USB port but not when installed internally.
The iFixit visual instructions were excellent and the repair went well. Since I don't have tools, I appreciate that iFixit identified which tools were needed and allowed me to order them along with the replacement part.
The HD cable appears to be a serious problem. Others have experienced this problem after about 2 years of use. I don't have any advice other than not to depend too much on any one computer.
Phillips #00 Screwdriver
MacBook Pro 13" Unibody (Mid 2009-Mid 2010) Hard Drive Cable