18.04 with AMD graphics card: black screen on boot, cursor in recovery mode

Solution 1:

today I installed Lubuntu 19.04 (x64) on an small EeePC with C6 dual core AMD processor and Radeon HD6290, and I was getting a black screen on every login screen.

Tried the 'nomodeset', but it didn't work.

But I did notice that if I closed the netbook lid, and opened it again, it would go to sleep mode, and then it could be woken up running fine.

It was not really a graphical driver problem, but instead the screen would just change the backlight to an off state at the login screen.

After some searching around, I followed the instructions from here: https://www.debugpoint.com/2016/10/2-ways-fix-laptop-brightness-problem-ubuntu-linux/

So I opened: sudo nano /etc/default/grub

Modified this line: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to be: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"

Save the file, close text editor, then run:

sudo update-grub

and reboot.

This worked for me :)