[winnersmw]

A few months ago my auto-brightness suddenly, seemingly randomly, stopped working. Checking the auto-brightness box no longer causes any changes to the screen brightness. For instance, manually setting the brightness to 50% and then checking the auto box doesn't have any effect—the brightness remains at 50% regardless of lighting conditions. I downloaded a sensor testing app and verified that covering the ambient light sensor with my hand was reflected in the app chart of ambient light information from the sensor, so the sensor is not physically broken.

When Verizon released the most recent update to the S5, the problem was fixed upon the phone rebooting but within 5 minutes stopped working again. So it is a software bug, and it has persisted across an OS update.

Is anyone else experiencing this issue? When googling and searching AC, I found some people who were having issues with the auto-brightness simply not giving the screen enough brightness, but it sounds like in those cases the auto-brightness is at least doing something... just not enough for their liking.

Any suggestions?

[B. Diddy]

You could always try booting into Recovery and wiping the cache partition: Reset: Samsung Galaxy S 5 | T-Mobile Support

Also try booting into Safe Mode (steps are at the bottom of the article). If the problem goes away in Safe Mode, then something you installed is interfering--it's just hard to know which one.