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I have a mid 2012 MacBook Pro 13" After the HD crash I bought a new 500 GB SSD. I put it in an external caddy, attached it via USB to computer and cloned the hard disk by recovering from the old disk using disk recovery. SSD will boot while in the caddy but not when installed into the laptop. It is possible to access the files on the SSD while in the laptop but if I boot from the HDD in a caddy or from a USB Boot thumb drive I cannot see the SSD in the set startup disk menu. When I insert the old hard disk in the computer it boots normally. This would appear to rule out hard disk cable problems (I replaced the hard disk ribbon cable last year). Any ideas as to what is wrong? SSD is a crucial MX300. Thank you.
That hard drive cable is probably your problem again. Apple is even replacing it for free on this model. I put pads on either side of it where it comes over the top and onto the optical drive. The bottom of the case tends to contact it there and damage it. Also, did you format the drive for Mac. Needs to be GUID. It will boot externally from a Master Boot Block format but not internally.
You may need to redo your drive (reformat it & re-install the OS) as many cloning apps mess up the newer versions of OS-X/MacOS. I don’t recommend using 3rd party cloning apps any longer. If you need to clone then use the one within Apples Disk Utility. Its best to use the built-in migration assistant function in the OS installer or run it afterwards from the Utility folder in the application folder. Here’s a bit more on it: Move your content to a new Mac
Hi, Had this problem on my MacBook Pro 13’ 2012 unibody. I had to change the internal SATA cable, I think the issue is not that the cables are faulty but they have some incompatibility issues with newer hard drives, especially solid state drives. I also run a data doubler with an SSD and needed to change the optical SATA cable connecting this drive because again I was met with the dreaded question mark on boot. Thanks, iloveCocolade
