2013 rMBP brightness not working

[stract]

I just noticed this tonight so I'm not sure how long it's been going on, but my screen was full bright when I woke my laptop tonight. The F1/F2 keys did nothing to adjust the actual brightness even though the brightness scale displayed on the screen while the buttons were being pushed.

I had not yet upgraded to 10.10.1., but I have now, with no change in behavior.

A suggestion to sleep and awaken the computer did not fix the problem. Nor did a restart. Any help would be appreciated! I'm being blinded here, not to mention the extra battery drain this must be causing.

I have a 13" 2013 rMBP.

 

[stract]

no change in behavior when connected to power source vs running on battery either.

 

[MacInTO]

That's a strange situation!

Here's a thread that might help, https://discussions.apple.com/thread/5976203

 

[stract]

so it appears the brightness was reset when I connected my laptop to my Apple tv via airplay. not sure how or why that happened, but it's suddenly working normally again. No idea what I did to fix it, but the problem is resolved (for now).