I have quite a similar problem. I upgraded my MBP 13" mid 2012 with a Samsung 250gb 860 EVO 2.5" SSD. I've done tons of research before I proceeded changing my MBP drive with an SSD. However, my macbook is acting wierd with the SSD but not with the HDD.
my problem is:
- when I turn on my macbook, halfway through the bootup loading screen it shows a "Prohibitory sign" ( which means a valid start-up disk has not yet been found), after a few minutes the screen shuts off then turns on and displays the loading screen and continues to complete the bootup. After the bootup is complete it takes few minutes to load up the mac OS interface and Once I'm on the mac OS interface everything is so slow and sluggish, whenever I moved my mouse or even open a folder or anything my cursor keeps on turning into a colorful spinning wheel.
I have tried:
- tried cloning the factory drive to the SSD using Carbon Copy and I have reset PRAM..
- tried installing a fresh copy of Mac OS from a USB stick and external hard drive.
-tried creating an external bootable drive by installing the Mac OS on the SSD using SATA to USB cable
-tried system preferences and set Startup Disk setting to be SSD
The SSD is working fine, I tried it on my sisters MBP 13" mid 2012 and it was working perfectly fine.
I also, tried booting up my mac with the external bootable SSD drive using SATA to USB cable and it works perfectly fine. However, when I install the SSD on the mac the problem occurs again. So, I was thinking it could be the sata cable. Next, I tried using a different hard drive and also tested my sisters MBP hard drive on my mac and it boot up just fine.
My findings was that my MBP doesn't like the SSD but works well with any other HDD.
I have not tried using a different SSD,
I have not tried changing the sata cable yet.
What could be the problem?
-tried the SSD on my sisters MBP 13" mid 2012 and it work perfectly fine.
and tried all possible way I could think off. I tried the