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Samsung 860 EVO not recognized on my MacBook Pro mid 2010 15". After replacing the HDD I turned on the MacBook and all I saw on the screen was question mark flashing in the middle of the window. What should I do please?
First, did you transfer data or install an Operating system on that drive? If you just installed the drive right out of the box nothing will show up. If you do have an OS on the Drive, Power on the laptop holding the option key. This will show you a list of Bootable devices available. If your drive doesn’t show up here then double check the Cable for any marks or damage. These are fragile and may have be damaged during install. Try installing the original HD and see if that shows up again. If it does, You may have a bad drive or the data has issues and needs a reinstall.
Are you able to connect your old HDD via a SATA to USB adapter cable like this one? StarTech 2.5" SATA to USB adapter cable If you can you can leverage your old HDD as the boot drive and then from it run Disk Utility to prep your SSD and then install a fresh copy of OS. If you can’t do that then depending on the OS-X your system was running you should have Internet recovery. Presss and hold the Command (⌘) and R keys to gain access. You’ll need either a wired or WiFi network to connect to the internet and depending on your service it may take awhile. Then run Disk Utility to prep your SSD and then install a fresh copy of OS. I do strongly recommend you stick with Sierra as the highest version you should go with. High Siera has some issues and Mojave is not supported by Apple on your system. Reference: Mac startup key combinations
