New SSD boot problems.
I have a mid 2012 MacBook Pro 13". After a crash I bought a new 525 gb ssd disk.
I put it in an external caddy, attached it via usb to computer and cloned the hard disk by recovering from the old disk using disk recovery.
SSD will boot while in the caddy but not when installed into the laptop. It is possible to access the files on the ssd while in the laptop but if I boot from the hard disk in a caddy or from a usb key I cannot see the ssd in the set startup disk menu.
When I insert the old hard disk in the computer it boots normally.
This would appear to rule out hard disk cable problems ( I replaced the hard disk ribbon cable last year).
Any ideas as to what is wrong?.
SSD is a crucial MX300. Thank you.
Is this a good question?