MacBook Pro suddenly started to freeze with any action (using SSD) I'm having a trouble with my MacBook Pro (Mid 2012).

I have upgraded it (5 months ago) to use a Kingston SSD instead of a SATA, and everything was perfect. Very fast and smooth...until yesterday. I was working and then when it was time to go home, i just pull down the monitor and the macbook went to sleep. When i came home and open my MacBook, it was just a disaster, EVERY SINGLE action, even click on any button, causes to freeze and the apple colorful ball (loading) appears.

Today i tried to put another SSD (samsung) to test if was my SSD that has a problem, but the problem remained. Then i tried to use a simple SATA and everything is normal (i'm asking now from my macbook with a SATA HD).

What do you think it could be?

This are my configs:
 - MacBook Pro Mid 2012
 - 13"
 - i7
 - 12Gb RAM
 - Intel graphics 1024
 - El Capitain OS X

p.s.: My SSD is almost full.
It sounds like you have a faulty SATA cable. Others have reported this same problem when upgrading from a standard HD to a SSD with Mid-2012 MacBook Pro laptops.

You can find more information over at Apple’s Support site:
https://discussions.apple.com/message/24783957#24783957