Vertical lines on MBP when screen is at a low power level

[afultz075]

I just restarted my MBP while sitting in the dark in my room and I noticed on the bootup screen there are vertical-running scan lines when the screen is on low power. There seem to disappear as the brightness setting goes up. I never noticed this before. Is this normal?

 

[mmmoussa]

Yeah, I've noticed that on my 15" MBP as well. I was thinking of having it looked at, but since I never turn the brightness down that low, I didn't see the point. Glad to know I'm not the only one who's noticed it though.

 

[Trepex]

I just restarted my MBP while sitting in the dark in my room and I noticed on the bootup screen there are vertical-running scan lines when the screen is on low power. There seem to disappear as the brightness setting goes up. I never noticed this before. Is this normal?

By "vertical running" do you mean these horizontal waves that travel from the bottom of the screen to the top? A lot of people have experienced them, and doing a PRAM reset 4x (hear the chime 4 times before letting go of the key combo) seems to get rid of them in all cases. Mine were also only really visible on lower brightness settings or on certain backgrounds like the solid blue one.

 

[Megatron]

Just wanted to add that I just noticed the vertical scan lines, and after searching and finding this post, I reset the PRAM, and it fixed it. Thanks guys!

 

[afultz075]

PRAM reset fixed it. Thanks!