Replacing MacBook Pro 15" Unibody (Mid 2009) Hard Drive Cable
My three year old MacBook Pro started showing trouble at startup, and after trying to move the hard drive to the optical drive using a "data doubler", I realized the hard drive was beyond repair. However, when trying to install a fresh hard drive at the usual station, and this did not show up as it should have, I took a guess that it might have been the hard drive cable that was defective.
A different issue with this troublesome Mac was that the cooling of the GPU did not seem to function properly, and the display went black apparently randomly, but mostly when a lot was going on on the MacBook. Twisting the pressing on the MacBook turned on the display again, but I decided to replace the thermal paste on the GPU to see if this would fix the problem. After following instructions to do so on iFixit.com, the problem was as bad or even worse than before. However, I have now put on a little bit more thermal paste and tightened all screws, and the problem seems to have been reduced.
The repair went smoothly. So smoothly that I did not take pictures.
If your mac breaks down, It might be both the hard drive and the cable.. Also, when screwing stuff back in, be sure to not pressing or jamming any of the thin cables to the MagSafe port, as this may prevent the battery from charging.