I agree with what maflynn wrote regarding CCC.
OP --
If you don't have any luck, try this:
1. Get a USB3/SATA adapter/dongle like this (cheap):
https://www.amazon.com/Sabrent-2-5-...478&sr=1-2-spell&keywords=sabremt+usb3+to+ssd
2. Connect the OLD drive to the adapter.
3. Now, boot up from the OLD drive. Press the power on button and IMMEDIATELY hold down the option key, and KEEP HOLDING IT DOWN until the startup manager appears. Select the old drive with the pointer and hit return.
4. Do you get a good boot? Then, let's continue...
5. Before going further, I suggest you open Disk Utility and ERASE the internal SSD. Choose "Mac OS extended with journaling enabled, GUID partition format". Let DU do its thing, and when the erased SSD shows up on the desktop, give it a name you like
6. Now, download CarbonCopyCloner from here:
http://www.bombich.com/download.html
(CCC is FREE to download and use for 30 days -- this will cost you nothing)
BE AWARE that if you use an older version of the OS, you might need an earlier version of CCC. They have a page for older version downloads.
7. Once you have CCC, open it and accept the defaults. Put your source drive (the OLD drive) on the left. Put the target (the SSD) in the middle. Click clone.
8. If CCC asks if you want to clone over the recovery partition also, YES, you want to do this.
9. Let CCC do its thing. It will take a while. BE PATIENT.
10. When done, power down. Disconnect the old drive.
11. Press the power on button and AGAIN repeat the trick you used above with the option key to bring up the startup manager. The new SSD should appear. Select it with the pointer and hit return.
12. Now, THE MOMENT OF TRUTH. Do you get a good boot?
13. If you do, GREAT, you're almost done, but one more thing:
14. Open System Preferences, select startup disk. Click the lock and enter your password. Select the SSD (it should be the only choice, but select it anyway) and close system prefs.
15. Final step: REBOOT one more time. Do you "come right up" to the login screen?
If so, DONE.
PRINT OUT this post, and save it for reference.