Swapped hard drive not recognized

The video in my older Macbook Pro died. My son has a newer 2012 Pro but his hard drive died. I took the working drive out of my Pro (OSX.10.11) and put it in my son's machine. His Pro won't recognize the drive so I can't even see it on Disk Utilities. When I boot the machine you hear the hard drive spin up and a few minutes later, it spins down and the question folder appears.

I can boot it from my bootable partition on my external backup, but how do you reformat a drive that is not recognized by the OS?