Got such kind of problem directly from installation phase:
FAILED to start Load/Save #ness of backlight:acpi_video0
in a final installation goes well, but after in case of restart it is about 50/50 if the screen starts or not.
Browsed forum for a solution and found topic with the same name, but no solution there.
Tried that from wiki Manjaro:
Reactivating_the_Backlight (can not add links )
Also no result.
Have a ryzen 5 with Renoir GPU.
Maybe someone have any solution.
Thank you in advance!