I replaced my hard drive 6 months ago to something larger. I couldn't use my laptop without it freezing 2 to 10 times a day and couldn't transfer large amounts of data. So I opened it up and put in my original hard drive, only then did my laptop stop recognizing any internal hard drive that was connected; I could only boot up through an external drive. I then notice the hard drive cable was slightly torn.
iFixIt is great. If it wasn't for this site, I would have had to replace my entire laptop after only two years. After replacing the cable, my laptop is running better than ever. The instructins on the site were exact and very easy to follow. Took me only 10 minutes to replace the cable and have my laptop up and running again.
Be careful with the cable because it is very fragile and the fact that they don't make these cables anymore for this particular model, it's good to be careful. Apple doesn't carry the part, nor do they have any idea what the part is.