(ISSUE) Replacing Broken HDD with SSD - 13" Macbook Pro 2012

[Sengial]

Hi! This if my first post so sorry if I'm not abiding by certain guidelines. My Internal Hard Drive was making a clicking sound and was extremely slow to boot up. If I log in, it loads for a while, goes to a black screen for a while, then goes back to the logging on screen. I decided to replace it with an SSD that wasnt in use (Sandisk SSD Plus 240gb) and it didn't detect the drive. Afterwards, I installed OSX on the SSD in an external enclosure, no problem. After, I put it internally and it doesnt detect the OS. PLEASE HELP?!??!?

 

[T5BRICK]

The SATA cable may be bad.

 

[Samuelsan2001]

Yep a new SATA cable is probably needed they are notoriously flaky in the MBP from that vintage.

 

[keysofanxiety]

Thirded. SATA cable is faulty and is a very common issue on your model.

It's a super quick fix. Just make sure you buy a brand-new SATA cable rather than a refurb, else the problem will reoccur.

 

[Fishrrman]

OP:

Go to ifixit.com to see what's involved with cable replacement.
They also have a part number that you'll need.

You can either order from ifixit, or perhaps check ebay.