Chosen Solution
I upgraded to El Capitan prior to backing up of the original HDD which may have an effect or would it be the SATA cable.
I would start off by checking the systems firmware level. Review this Apple T/N: About EFI and SMC firmware updates for Intel-based Mac computers make sure yours is at or newer than the listed level for your system. How did you upgrade your drive? Did you use some cloning software or did you use the Migration function in the OS installer? Do you have a case to hold your old HD which you can connect to your system (USB or FireWire)? If you do hold the option key with the drive connected when you restart the system so you can select the external drive. Now run Disk Utility to test out the SSD using Disk First Aid. Did you get any errors?
