Recently, my Mid 2012 13-inch MacBook Pro displayed a blank, gray screen instead of booting up. I suspected there was a problem with the hard drive cable, so I took it in to a (non-Apple) repair shop to get a repair quote.
It turns out there was a problem with the cable, but they also said there was a problem with the hard drive. They said their tests revealed a “cyclic redundancy check” or CRC error which would necessitate total replacement of the hard drive.
I then took the MacBook apart, removed the drive, plugged it into another Mac with a usb-adapter and ran First Aid in Disk Utility.
Now, disk utility tells me there’s nothing wrong with the drive (big green check next to drive icon and no error messages.) I can also explore it in finder without issue.
So, my question is this: is it that disk utility does not recognize CRC errors where they exist, or is my hard drive actually fine and the repair shop people were wrong?