How can I get my 3rd party SSD to boot El Capitan? I have a Mid 2012 13 inch MacBook Pro that's been running successfully with a hybrid drive (3rd party) for the last few years.  Recently, the operating system crashed and the hard drive is no longer recognised in recovery mode, so I purchased a 500GB samsung SSD to go into the machine.

I can successfully install Mountain Lion or El Capitan on the new SSD, but it never boots.  I simply get any of folder with question mark / cancel symbol or flashing between the two when trying to run off that drive.  Here's what I've tried


Boot in Recovery Mode, format drive as 1 partition (Mac OS journaled and using the Guid Partition Map), and then install OS X.  This works successfully until trying to boot from the SSD.
Boot in recovery mode and try and restore from time machine backup.  This fails as it cannot create a recovery partition on the drive.
I've installed Mountain Lion successfully on an external USB drive, and have it up and running, from there, I downloaded the El Capitan installer and installed onto the SSD, which worked fine, but as soon as it came time to boot from the SSD, no dice.
I've created a USB installer from the El Capitan installer (using createinstallmedia), then used that USB drive to install to the SSD, and it all works to the point of trying to boot from the SSD, and then, no dice.
Throughout this process, Disk Utility in OS X and OS X recovery can successfully see and partition the SSD, and Verify Disk has never returned any errors, so as far as I can see, it doesn't seem to be hardware issue, but I cannot get OS X to boot from the disk (it boots fine from the USB I installed to).


Any ideas?

UPDATED: Just to clarify, in the Disk Utility in the El Capitan installer, I choose to partition the drive using the following options:


Name: OS X
Format: OS X Extended (Journaled)
Scheme: GUID Partition Map


This works without a problem, and the new partition appears. At this point, I choose "First Aid" which completes with no errors.  "Info" on the partition created, shows "writable" yes, but "bootable" no, which I would expect at this point.

UPDATED: I've successfully installed Ubuntu 15.04 on the hard drive and it's working fine, and then I swapped the 500GB drive with a 240GB Samsung SSD and got exactly the same issue.  Seems like I'll end up with Ubuntu on this machine, as I can't install either Mountain Lion, El Capitan or restore a Time Machine backup.
You could try using bless to verify whether the disk is recognised as bootable and to potentially bless the disk to make it bootable.

If you can boot into Single User Mode (hold down command-S while booting) or launch terminal from an installer disk you can run bless

First I would try to establish if the drive is bootable or is flagged as the boot drive all by using

bless --info /Volumes/yourSSDdrive The state of your drive's blessed system folder

bless --info The state of the current boot drive's blessed system folder

bless --getBoot The current actual logical boot volume (e.g. /dev/disk1 )

If you find your drive is not blessed, you can bless it yourself with 

bless --folder "/Volumes/yourSSDdrive/System/Library/CoreServices" --bootinfo --bootefi

See the man page for more details:
https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man8/bless.8.html