I am restating my question as posed on [my previous post](https://askubuntu.com/questions/1211400/screen-will-not-change-brightness-ubuntu-18-04-4-lts?noredirect=1#comment2035873_1211400).
I cannot change the brightness on my machine.

I have a Lenovo Ideapad (330S-15ARR - Type 81FB) running Ubuntu 18.04.4 with an AMD Ryzen 5 2500u with radeon vega mobile gfx × 8.

When running 

> 
> ls /sys/class/backlight
> 
> 
> 

the result is

```
acpi_video0

```

Has anyone else had a similar issue and found a resolution?

Apologies about my previous question not being detailed enough, I have been absent from tech for some time now.