Ubuntu – Black screen after reinstall/install nvidia driver

i have hard time to figure out what is the problem. After my screen going dim (lenovo Z500 brightness key problem) i change my grub to fix this.

Grub:

GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX="acpi_backlight=vendor"

Then i reinstall my kernel linux-image-4.13.0-43-generic. The problem with brightness was solvt but.. nvidia driver was not working.
Before or after restart i get notation that my computer can't detect Nvidia driver. I reinstall driver and i get black screen.

I try several times remove all nvidia drivers and install various versions [nvidia-396, nvidia-384, nvidia-340] of nvidia driver but each time result is the same. After installation and reboot i get black screen.

I have used all sorts of tips posted here
but nothing will work. After installation i check if driver is installed with nvidia-smi. One more thing i working with nvidia cuda to compute some data, don't know if this is linked to this problem.

After delete nvidia driver screen is working well on Intel gpu.

Any ideas what is the problem?

No Solution so far.

After help from my familiar computer scientist we can't found solution for this problem.

To solve this i had to to restore system using Timeshift tool.