How to solve Black Screen after NVIDIA graphics driver in Ubuntu?

1. make sure that Secure boot is disabled in BIOS

(https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/disabling-secure-boot)

 

2. check the latest certified graphics driver version at NVIDIA site
(https://www.nvidia.com/Download/Find.aspx?lang=en-us)

 

3. booting Recovery Mode (Saft Mode) in Ubuntu
(press ESC key while booting and then choose advanced options => recovery mode => root )
(https://www.maketecheasier.com/boot-recovery-mode-ubuntu/)

 

4. login with ID/PW

 

5. sudo apt-get update

 

6. sudo apt-get install nvidia-

(press TAB key twice, then the found version will be shown)

 

6. sudo apt-get install nvidia-390

 

7. sudo reboot