Flashing Question Mark Folder! 2012 Macbook Pro 13"
20 - 30 minuten
The main issue was that my hard drive was no longer being recognized, even after purchasing a brand new hard drive.
Here is (a long story) how I got there:
My 2012 Unibody Macbook Pro 13" started to lose its perform capabilities one day in January 2015. I was running Mavericks for a year so on 4GB RAM and haven't been experiencing slowdowns or heating until then. Not wanting to spend money on repair and short-on time with school, I did the recommended Repair Disk Utilities, PRAM resets, SMC resets, and overall cleaned my mac from unnecessary things. My biggest mistake was upgrading to Yosemite (40 hours) and the macbook became unusable. I upgraded my RAM to 8gb for $171 from a campus tech service (too expensive). It was still too slow so I put in rEFind boot manager so I could dual boot LinuxMint (its amazing). But suddenly the flashing question mark appeared instead of the boot loader.
The repair was simple. The instructions was clear and pictures accurate. I was concerned about static electricity zapping the internal components so I wore an anti-static strap.
After installing I turned the macbook on while pressing option key and my hard drive was found, with all the partitions I created as well. rEFind will not work so I can no longer boot into LinuxMint but the performance of Yosemite greatly improved after replacing the cable.
Don't overheat your computer. Don't upgrade to Yosemite unless it its a clean install. Although I may have some batter issue, for the time being, the cable is the BEST solution to a non responding hard drive. I wasted $165 (with shipping to Canada) on a brand new hard drive that didn't solve anything. If I went back to the campus tech guy I would've paid off two university courses. Fit it yourself!