Ubuntu 18.04 stopped working with NVIDIA drivers

I am running Ubuntu 18.04 on a CLEVO notebook and have the nvida-390 drivers and Cuda installed. It worked fine for a month, but - suddenly today it stopped working. I can still access the login screen, but the screen remains purple.

I've already tried to purge and reinstall the nvidia-390 drivers (I've also tried the 396 drivers version) without success. After the login the computer always stops working. I cannot even access tty. After purging the drivers I can login and all works fine with nouveau, but I really need Cuda for my work.

My specs:

• i7-6700HQ
• 8GB RAM
• Nvidia GeForce GTX 970M
• Intel Wireless 8260

Can someone please help me? Thanks.

You might need to have Direct Rendering Manager Kernel Mode Setting enabled on system boot.
NVIDIA driver's PRIME Synchronization support relies on DRM-KMS, which is disabled by default.
Find more comprehensive information in the discussion on the NVIDIA GPU Unix Graphics forum.

Execute sudo nano /etc/default/grub and add the parameter nvidia-drm.modeset=1 to the line GRUB_CMDLINE_LINUX_DEFAULT. Save the change you've made and run sudo update-grub.
Restart the Ubuntu operating system, and now everything should work properly, right as expected.

I was able to get it working with the latest Nvidia-418 drivers on a Lenovo W530 with the Nvidia GK107GLM Quadro K2000M:

1. Edit the sudo nano /etc/default/grub and remove "quiet splash" from GRUB_CMDLINE_LINUX_DEFAULT and then sudo update-grub (that may be similar then adding nvidia-drm.modeset=1)
2. Switch to LightDM: sudo dpkg-reconfigure lightdm (necessary so my second monitor was recognized)
3. Install PPA with latest drivers: sudo add-apt-repository ppa:graphics-drivers/ppa and sudo apt-get update
4. Install latest recommended driver (in my case Nvidia 418): sudo ubuntu-drivers autoinstall