After updating the system (Sierra 10.12), my Mac mini boots up until the progress bar is at about 50%, then display becomes simply black. The computer does not shut down, but display is simply black.
If I boot in verbose mode, the last line I see is the following:
IOConsoleusers: gIOScreenLockState 3, hs 0, bs 0, now 0, sm 0x0
Resetting the PRAM/NVRAM and resetting SMC do not help.
Internet recovery (Shift-Option-Command-R) does not help: recovery itself seems to proceed fine, but when it comes again to the Apple logo, the progress bar again reaches about 50% and the display becomes black.
Starting up in Recovery mode(Command-R) and starting up in Safe mode (Shift) do not help: as in Normal mode, it reaches 50% of progress bar and the display becomes black.
Apple Hardware test: no problems.
I can boot in single user mode (Command-S): "fsck -fy" does not find any problems. I don't know what other things I can do in single user mode.
As I understood after googling "IOConsoleusers: gIOScreenLockState 3, hs 0, bs 0, now 0, sm 0x0", my video card is not compatible with the new version of Sierra. What can I do? Can I install previous versions of macOS? How can I do that if I can boot only in single user mode?
Info:
Mac Mini 5,1
Dual Core Intel Core i5
Intel HD Graphics 3000