“Unable to unmount volume for repair” message from reformatted SSD in “Option/ALT startup” using bootable USB

I am trying to reformat a Samsung 512GB Pro with bootable USB, and I have manage to get through the prep for the USB. But after the "Option/ALT startup" i click on the USB to begin with and when the "Install OS X" page i get the "Unable to unmount volumet for repair" message.

Info about the MBP:

• 2012 model
• Used Yosemite when in function
• Intel Core i5
• 4 GB RAM
• 2,5 GHz

Info about the SSD:

• 1-2 years old
• Applied with, 1 patriot, OS Extended (journaled), GUID.
• Wiped clean, 448,5 MB remains.

Failed attempts:

• Repairing the disk in Disk Utility, same error.
• Using code "hdiutil eject disk0" and others in terminal to force the disk to unmount. Message back "Unable to unmount "Disk0" resource is busy".
• Removing the SSD from the MBP and connect it to an iMac. Repairing worked, but when reinstalled into the MBP same error occurs.