Display brightness not responding

Hi there iQuame,

We'd like to learn more to see how we can help with the display brightness on your Mac. If you use the increase brightness key or the decrease brightness key on the built-in keyboard, does that seem to make a difference? Learn more about how that works here: Change your Mac display’s brightness - Apple Support

If you boot up in safe mode, are you able to adjust the display brightness?

Safe mode prevents your Mac from loading certain software as it starts up, including login items, system extensions not required by macOS, and fonts not installed by macOS. It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. And it deletes some system caches, including font caches and the kernel cache, which are automatically created again as needed.

Safe mode is particularly useful when you're trying to resolve an issue that doesn't seem to be associated with using any particular app.

Dependent upon which type of Mac you have, the steps for booting up in safe mode can vary. Follow the relevant steps here:

Apple silicon

1. Shut down your Mac.

2. Turn on your Mac and continue to press and hold the power button until you see the startup options window.

3. Select your startup disk, then press and hold the Shift key while clicking “Continue in Safe Mode.”

4. Log in to your Mac. You might be asked to log in again.

Intel processor

1. Turn on or restart your Mac, then immediately press and hold the Shift key as your Mac starts up.

2. Release the key when you see the login window, then log in to your Mac. 

3. You might be asked to log in again. On either the first or second login window, you should see ”Safe Boot” in the upper-right corner of the window.

You'll find this information in this support article: How to use safe mode on your Mac - Apple Support

Let us know how it goes.

Cheers!