Chosen Solution
so i bought this laptop, the women claimed it was water damaged, i opened it up and there was no sigh of any damage, everything was working just super slow, i ordered a samsung 850 evo 250GB, got a bootable usb ready to install El Capitan, but it always gets stuck while starting up
OK, lets backup here… Using your other Mac via the SATA to USB adapter can you see the drive using Disk Utilities? Correct? If you can reformat the drive and create a new GUID partition map as well as create a Mac OS Extended (Journaled) partition. Once done from this same Mac, follow these steps: How to install OS X on an external drive connected to your Mac While this TN is assuming you are using it as a spare boot drive the steps are the same for setting up a fresh drive for another system. Jump to the ‘Install from your normal startup disk"
I would start off replacing the HD cable as they tend to breakdown. Here is the IFIXIT guide: MacBook Pro 13" Unibody Early 2011 Hard Drive Cable Replacement and this is the cable you want as it’s the improved version: MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable. But before you do that visit any Apple Store as Apple has been replacing them for free for a lot of people. Put the original drive back in before you go. Let us know how it goes.
