When I updated my Mac to macOS Big Sur 11.6, I immediately found that I couldn’t control my screen brightness, and the brightness was stuck at around 50-75%.
The keyboard brightness control can’t work at all, and the brightness slider in the Control Center is grayed out.
How to fix my issue?
That’s so weird! I saw many Mac users encountered this issue after Big Sur updates.
Maybe you can try to disable Auto-brightness?
Apple menu > System Settings > Displays > Uncheck the box labeled Automatically adjust brightness.
Have you tried resetting NVRAM/PRAM?
Sometimes resetting the NVRAM (non-volatile random access memory) or PRAM (parameter random access memory) can resolve display issues:
- Shut down your Mac.
- Turn it on and immediately press and hold Option + Command + P + R for about 20 seconds.
- Release the keys when the Mac restarts.
Once restarted, try adjusting the brightness again.
Mac Safe Mode can help you see the problem. You can enter Mac Safe Mode to see whether the problem still remains.
- For Intel Macs: Shut down your Mac, turn it on, and immediately press and hold the Shift key until the login screen appears.
- For Apple Silicon Macs: Shut down your Mac, press and hold the power button until the startup options appear, then select your startup disk and press the Shift key to boot into Safe Mode.
Once in Safe Mode, try adjusting the brightness. If it works, the problem might be caused by third-party software.
(1) Some accessibility settings might affect brightness:
Go to System Settings > Accessibility > Display.
Ensure that Display Contrast and Invert Colors are turned off, and Reduce Transparency is unchecked.
(2) Night Shift and True Tone adjust the screen color temperature based on time and ambient light, which can make the display seem dim:
Go to System Settings > Displays, and turn off both Night Shift and True Tone.
Check if this improves brightness control.
(3)Reinstall macOS or upgrade to macOS Monterey…