My samsung s8 when just unlocked from idle, it behave normally with normal screen tone. However after a while, sometime it will turn yellowish with dark horizontal lines. When this happen, the screen is barely readable.

But if I lower down the brightness say 20%, or brighten all the way to 70 to 100%, its then normal again.

Is this something to do with LCD or the voltage issue?

Appreciate advise from sifu

Not using S8, but my note 9 seems to have similar issues. Your best course of action is to head over to the service centre and change it.

Well mine is out of warranty for long. If it cost a thousand to fix it, i might as well change the phone

Problem is no one seems to be able to tell me what's going on, be it motherboard or LCD or anything else. Was thinking if anyone in the forum faces such issue before and how it can be resolved to make up my decision

I know another user in note 9 also faced the same issue. The SC told him there's a micro crack on the screen that was not visible until the SC showed him. And he took photos of how the screen looked like, the problem was the same as mine. But the SC told me it's charging issue. So no one knows, except that theres clearly an issue with the screen.