Brightness control not working.

Display brigntness (F1 and F2 keys) or keyboard backlight brightness (F9 and F10)?

If you mean keyboard brightness, those only work in dim light (when the keys are lit already - place something opaque over both speakers to test that).

May I add to your posting by saying I have the same problem occur at least once every day, but only after I open the MacBook Pro from sleep, with the top down.

If the screen is open when it goes to sleep, no problem; but when I have to pull the screen up to wake the computer, the display comes on at the brightest setting and cannot be controlled, not even from the System Preferences>Display, until I restart the compter.

I'm having same problem with MacBook Pro that is less than a month old. I reboot and it works, but then with in the day it stops working. Maybe it is related to after it goes to sleep. Also, when I turn back on the setting to adjust to ambient light, that setting doesn't work either.

Ok, I just found a better work around. I randomly tried holding down the apple/command key while I pressed the brightness controls, and suddenly they came back to life and worked! Much better alternative to rebooting, but hopefully this problem is fixed in next software update.

Thanks for the lucky work-around. It worked for me as well, and the conditions (set up) for my problem were the same as what has been described in this thread.

I too have the same problem after the last MacBook Pro update. My brightness keys do not function, and the brightness is no longer available in the Displays Preferences. I am stuck with a dim screen. Barely usable in daylight.

To further clarify. My brightness buttons don't work. There are no brightness controls in the Displays Preferences panes. I tried deleting all of the Apple system preferences, but that didn't help. I also repaired permissions, and that didn't help. This problem occurred after the last MacBook system update last week.

Same problem here. Actually, I've had it for a while: no brightness control by fn+f1/f2 or display settings. I used Light Me for a while but this stopped working as well. Quite annoying.

Thx for posting this solution but it doesn't work for me.

On startup, neither the F9 or F10 brightness keys work. I have to go into System Preferences>Display and then use the "Brightness" Slider bar to adjust it. Very annoying.

Only had this Intel-based MacBook Pro for a few days (received on 10/1) and already an issue.

Not happy.

same issue here - started this AM - Volume controls seem to not work either - other keys work fine - woked fine yesterday - macbook is 1 week old.

so- for those interested mine is fixed as of this evening - it took me a little thinking - but it turns out I had used both an older keyboard and one of the new ones. [new one at office - old one @ home]. and had neglected to run the software install. in any case, based on one of the above comments - I thought perhaps the external keyboard issue was linked to the mac keyboard issue.

so - I plugged in the new keyboard and ran the software update - after which both keyboards are now working properly. so it appears as if there is some kind of requirement within the firmware that requires the new update, however the update will not run if if one of the new keyboards is not installed at the time of update.

Hope this helps
b

+On startup, neither the F9 or F10 brightness keys work. I have to go into System Preferences>Display and then use the "Brightness" Slider bar to adjust it. Very annoying.+

F1 and F2 control the *screen brightness*, F9 and F10 are the *backlit keyboard* and will only be active if the ambient light is low enough, cover both speakers to activate them ...

Thanks for posting this workaround.
I had the same problem, and this worked for me 🙂

Cheers.

update#2 - after disconnecting from new keyboard - problem re-appears - no software update appears availabe for a consistent fix