MacBook HHD to SSD swap issue

Hi all, I am having a problem with installing a new SSD into my old MacBook Pro (mid-2012). Got it formatted and partitioned( Mac-Journaled). Transferred all the files to a new drive from the old one. Installed it, but no booting. “Question file folder” is on the screen. I’ve opened a disk utility in a recovery mode. SSD and a data disk are shown there. But when I go to a startup disk menu it doesn’t show any disks I can choose from. After shutdown and restart the same “question mark” is appearing on the screen. What puzzles me is that I am able to boot and load OS X with the same SSD if use it as an external drive. Has anyone experienced similar issue? Has anyone found a solution? Appreciate if you can share your experience in resolving it? Thank you