08-11-2013, 09:54 PM
The plot thickens. I didn't have access to an external hard drive case, but I did have access to a friend's MacBook Pro. I swapped my supposedly defective (old) hard drive into his MBP and tried to boot up. Lo and behold, my desktop appeared! I took the opportunity to scavenge my most important files onto an external hard drive; I didn't want to try a full back up, since I'd once gotten my old HD to boot on my own MBP, but trying to back up caused the system to lock up.
Afterward, I turned the MBP and on again. This time, the HD would not boot. A repetitive clicking noise could be heard, similar to what I heard on my own system after problems started developing. I managed to get the system into the disk utility after a reboot, and DU strangely said the HD appeared to be okay (despite not booting up before or after the scan). My friend's own HD worked just fine in his MBP after we swapped back.
I tried installing the OS on my external HD and have had absolutely no problems with that. This gives me hope, since I wouldn't have expected that to work if there were issues with the logic board.
Given this info, how certain are we that the SATA cable is the culprit? I can't help but think that my old internal HD is at least somewhat damaged, since it presented issues even in my friend's MBP. Am I correct in thinking that, if the logic board were the culprit, I wouldn't be able to boot up even from an external HD?