I've got a Pascal nvidia card that Ubuntu doesn't understand, and instead of automatically booting into a low graphics mode it just blanks the screen. I could install Ubuntu by editing boot parameters and using nomodeset but I can't do that once it's installed. Holding down right or left shift does nothing. Is there a way I can boot into Ubuntu?
SnapOverflow
You can use the boot repair tool to reinstall grub with a menu delay. This will allow you to add the nomodeset option to your kernel by pressing 'e'.
https://help.ubuntu.com/community/Boot-Repair
Once booted, enable the nvidia driver in the 'additional drivers' application and reboot the computer, this time without changing the boot settings.