Chosen Solution
Hello, my macbook wouldn’t boot one day so I tried to fix it but ended up reinstalling mac OS El Capitan on my 512GB samsung SSD that i use in it. I tested the ssd with crystal disk info, and it said it was 99% good. I have a carbon copy cloned backup on a 2.5" 5400rpm and I installed it in my computer (internal 2.5" slot) for awhile, and it worked fine, albeit very slowly, almost unusably. Then I restored and reinstalled mac os on my SSD in an external enclosure (since it wouldn’t install while it was inside), and it worked fine in there. when i try to boot it from the interal interface in verbose mood, i get “Sata warning: enable drive phy pm failed”, but from the external enclosure it works fast and everything. I want to buy a new sata cable to fix the problem because i’m tired of booting from an external USB3 drive and never being able to wake it from sleep (it gives me the rainbow wheel of death when i try), but i’m worried that there’s a chance it’s not the problem since it works just fine with the backup harddrive. Would you recommend buying a new cable?
This issue actually sounds like you failed to format the drive GUID and Mac Extended first. It will work externally with Master Boot Block but not internally so check that first, Cloning used to be the way to go but by doing it you lose the repair and reinstall partition. Better to do an internet reinstall where you get the partition then use Migration Assistant to move your data and apps. Next those cable do get damaged as they come over the last step where the bottom hits the cable.
