Quick and easy fix a repair shop would have charged a small fortune for. The only thing I'd add is if your replacement has built in glue like mine did be careful installing it as it will stick anywhere and everywhere!
We upgraded our hdd to an ssd and in the process must have damaged the sata cable. Macbook worked for a month before we got the flashing ? folder of death. Investigating we noticed the cable was partly ripped. This guide was perfect for replacing the cable, and now the macbook is working fine again! Brilliant! Just be careful to anyone replacing the hdd, the sata cable can tear easily.
I've replaced my hard drive cable twice now. The problem seems to be that the underside of the aluminum unibody has small ridges on it (you can see them, but they are small. The cable rubbed back and forth on these ridges, and you could see where the cable had shorted where it had worn away. It doesn't take much.
I found a youtube fix which involved only laying a piece of electrical tape along the underside of the cable (underneath the drive), and another piece along the body itself. A couple minutes and few cents worth of electrical tape later and all was working fine.
I think i might have damaged the yellow ribbon that needs to be reinserted into the new sata cable because i recently installed one and had it fail 2 weeks later and just got a new one that isn't loading up the sign-in menu but at least begins to read the hard drive instead of going straight to the ' ? ' folder. However, it will just continue to read the hard drive and stay at the loading screen with the apple icon and a spinning gray loading wheel below it without any progress. Any thoughts? I was thinking the yellow cable could have somehow been damaged. Does anyone know the name of the part with the yellow ribbon? It is connected to the bracket that sits below the hard drive.