Lollipop brightness changing by itself (not on auto)

[lebatte]

Several times now, I've noticed that my screen brightness is changing by itself, making it either 0% or 100% bright. I'm on T-Mobile, if that makes a difference.

I start on Auto Brightness and then move the slider to where I want to keep the brightness (thereby unchecking the Auto option), and then let my screen turn off. When I turn my screen back on, once in a while, the brightness will either be turned all the way down or all the way up. This is particularly unnerving during the day, when 0% brightness makes it look like my phone isn't turning on, and at night, when 100% brightness is practically blinding.

Anyone else having this issue?

 

[B. Diddy]

Welcome to Android Central! You don't have any power saving options turned on, do you?

 

[lebatte]

Thanks! Nope, I don't. I may have in the past, but it just happened several minutes ago without any power saving options turned on.

I had set my brightness to maybe 1/6th of the way from the bottom, which was definitely bright enough to see the screen come on. A few minutes later, I went to turn on the screen, and it was so low that I couldn't even see that the lock screen came up. 0% brightness. I went into the brightness settings, and Auto was still unchecked (and if it were checked, the screen would be brighter because I'm in a fairly bright indoor environment). I'm pretty positive the slider was all the way at the bottom when I went into the brightness settings. Totally moved there by itself.

 

[B. Diddy]

Ugh, hopefully this isn't another bug that came with the Lollipop update. Have you tried wiping the cache partition? http://support.t-mobile.com/docs/DOC-10404

 

[lebatte]

I wiped the cache a couple of hours ago as you suggested. The brightness issue just happened again. And I confirmed this time that the slider did actually move itself down to 0% brightness.

Just a thought: I've seen other people talking about Lollipop's brightness settings, and how apparently they changed to let you stay on Auto while picking the midpoint for the auto brightening/dimming using the slider. That doesn't seem to be the case with me—when I move the slider, Auto gets unchecked. Is this something specific to the S5 on T-Mobile? Could it be related?

 

[B. Diddy]

Sorry, I don't specifically how it works on the S5. One other thing to try is to boot into Safe Mode, in case some 3rd party app is doing this. Safe Mode steps are at the bottom of that linked article in the previous post.

 

[Lisa Edge]

I am having this same issue. I'm with ATT and have s5 active.