Cannot get GeForce GTX980Ti working with ubuntu 16.04

I have an ASUS motherboard deluxe and am trying to use GeForce GTX 980 Ti with Ubuntu.

I did the following in the terminal:

sudo apt-get purge nvidia*
sudo add-apt-repository ppa:graphics-drivers
sudo apt-get update
sudo apt-get install nvidia-384

Then I reboot. When I try to login, I get a black screen with a white line that says:

/dev/sdb2: clean, 291272/4292608 files, 480345/18174432 blocks

and it won’t login. I can remove the nvidia driver by doing ctrl+alt+f2 then doing

sudo apt-get purge nvidia*

Then I can log in but the gtx 980 ti is using the nouveau driver again, as lscpi -v shows.

I tried what was suggested in:

https://askubuntu.com/questions/383636/12-04-3-can-start-only-after-i-press-resume-in-rescue-mode-every-boot-prob/391608#391608

which is to do

sudo vi /etc/default/grub

and add nomodeset:

GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash nomodeset”

Reinstall the nvidia driver, try to login and then run nvidia-bug-report.sh and attach the tar.gz file it creates to your post.
The script might be located in /usr/lib/nvidia-384/bin/nvidia-bug-report.sh