Have a 5,1 with a GTX1080 inside it. Without thinking I hit the update button in OS X today, and only once it shut down and started installing did I realize what I had done...after a while the screen went black and wouldn't come back on, I assumed it had finished and had rebooted to the desktop now obviously with no GPU drivers. Turned it off, swapped in my 680, rebooted. After rebooting with the 680, still nothing. Shut it down again, made sure it was seated probably, rebooted, still nothing. My display is getting no kind of signal from the 680 at all. Fan is spinning, but seemingly nothing else is happening. Wondering what my options are at this point...OS is on a PCIE SSD, so I suppose worst-case scenario I could buy an enclosure and boot my old MacBook Pro from that drive, make sure the OS update went through, then wait for the Nvidia driver to get an update and then update that? I'm not sure what else to do. Also have no idea why my 680 isn't working all of a sudden...also very confused by that. Thanks in advance.