Folder With Question Mark After SSD Upgrade And OS Reinstall

Hi everyone! I have a problem with my friend’s iMac mid 2010 that i’m fixing. I’ve changed his hard drive with a ssd (samsung 850 evo) and after reinstalling the OS via recovery (cmd+R) mode it shows a folder with a question mark in it during the boot.

I searched some solutions and until now this is what i did:

1)Tried another hard disk (used a 2.5” mechanical drive that I generally use for backups) and it worked on this one.

2)Tried upgrading the sata cable with a new one but it didn’t work (by the way changing a sata here is a total trip to !&&*!)

3)Run First Aid From Disk Utility. The ssd is ok.

http://imgur.com/y7HJtl7

4) Tried to select the Startup Disk, but the ssd doesn’t show!!! What’s strange is that i can see the ssd on disk utility and can even perform the OS installation.

http://imgur.com/P4VmcpA

http://imgur.com/wAwQfJR

http://imgur.com/Eid4gXh

5) Tried NVRAM reset (cmd+opt+R+P) and it didn’t work. 6) Connected the ssd to my PC via a sata to usb cable to check if it works and it works correctly.

The crazy thing is that I can erase the SSD with disk utility, I can reinstall the OS and at the end of the installation, after the reboot, it shows the folder with the question mark.

What else can I do?? Thanks you all guys!