Macbook Pro 13" mid 2009, man I am having issues.

It all started with what I thought to be my hard drive failing. Programs acting up, all my Ram being eaten without reason, getting a grey screen telling me that I must restart my computer manually. Restarts taking an hour.

So I buy a new Hard drive, and new Ram to boot. Ram works perfectly. Hard drive...refused to be recognized inside my Macbook. Ran disk utility and all that jazz, it just wouldn't show up anywhere, yet putting in my old HD would sort of work, just take a year to start up, and usually crash within 10 minutes.

So I connected my NEW Hard drive as an external- it was recognized that way. Installed OS on it and that is how I have been running my Macbook.

So, is the cord that connects the hard drive to the computer inside my laptop busted? I don't know how to tell. I tried putting my new hard drive inside again after installing OS on it, still no go there. Aside from the inconvenience of running off an external, my laptop is running like new...except for the keyboard!

Yes, the keyboard. Since I've been running off my hard drive as an external, my keyboard has become randomly unresponsive. It seems to mostly be the keys "e" through "o." Is this just caused from lag from running off an external? Or do I have ANOTHER cable going bad at the same time as my HD cable? I am using a USB keyboard right now with no issues at all, if that helps.

I'm going insane. I just need to know if I need to buy these new cords before wasting the money I barely have to begin with, and if anyone could tell me the technical name for these cables so I can buy them online, that would be great. Thanks in advance.

First off, what size hard drive did you buy, what speed, physical demensions, and transfer rate? If I just confused you, just post the link of the exact drive you purchased, or model number might be enough.

Second, did you purchase this to replace a failing drive?

Wow - I am having pretty much the same issue with the hard drive on my MBP 13" Mid 2009!

My original drive doesn't boot but IS seen in Disk Utility (unable to be repaired or partitioned however). I purchased a new 120GB SSD from OWC and it is not recognized in Disk Utility if I use it as an internal drive. If I use it as an external drive, it shows up fine and I have install OS X and updated software and all.

Before replacing the drive, I had taking it in to the Genius Bar and they kept it overnight and then told me the drive was bad BUT the hard drive cable was good. So I'm pretty confused and frustrated now.

The hard drive cable part number is 922-9062 and here are some places online that have it:
MacBook Pro 13" Unibody (Mid 2009/Mid 2010) Hard Drive Cable (922-9062) - iFixit
https://www.usedmac.com/products/922-9062-macbook-pro-13-unibody-hard-drive-cable
922-9062 $24.00 - MacBook Pro(13-inch) HD Cable

I'm going to visit the Genius Bar again and see if they can triage some more and if it is the cable I want to find out what it will cost and how long it will take. I'd prefer to fix these things myself but getting the parts from somewhere online will just delay the repair even longer.