Black screen on login after update

[atowler]

I tried the following:

sudo apt-get purge nvidia-370
sudo mv /etc/X11/xorg.conf.bak
sudo apt-get install nvidia-370
sudo prime-select nvidia
sudo reboot

but I was still greeted by a black screen when my laptop rebooted. Interestingly, I can type my password and press enter and I hear the login sound.

Please try with driver 364 and instead of selecting nvidia, first try with prime-select intel, then login and use the nvidia graphics tool to select the nvidia card, then logout and login back.

I just tried this and it won't switch to nvidia using prime-select or using nvidia-settings. It says it switched but when I reboot or logout it's still in intel mode according to the nvidia tool. Interestingly, prime-select says that mode is unknown when I issue `prime-select query`. I tried starting up a game and it's clearly still in Intel mode.