My K56CB BIOS is very dark WHY!!!

[Nay]

That happened so suddenly after I turn on my laptop... I wasn't did anything before, just run Ubuntu and brightness control in OS seems to be fine
PS#1.There's a weird screen flickering happened anytime that I use my laptop
PS#2.All laptop parts are original, nothing change from 8 years ago (battery life = 0%)
PS#3.I didn't tried in Windows until now


Thanks for help >~<

[Nay]

Ploblem is now fixed when install windows... Thx