Auto brightness not working in my iMac

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Level 1

11 points

Auto brightness not working in my iMac

After i changed manually my brightness, the auto brightness stoped working all together. It has several days like this and i don't know what to do...

i have tried the reset, turn it on and off, changing the lighting settings in my room and nothing of that has worked...

Thanks for the help in advance

iMac 21,5" with the 4k screen, latest High Sierra version installed

iMac, iOS 11.2.6

Posted on Feb 27, 2018 8:57 PM

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Answer 1

Best reply

chuck_3rd

Community Specialist

Mar 1, 2018 10:18 PM in response to JacoboMateo

Hi Jacobo,

Thanks for giving that a shot for us.

Let's try another couple options to determine what the issue could be.

If it's a software conflict, we can try to isolate that by using safe mode as a test. If it works correctly in safe mode, try disabling some Login Items that might be affecting that:
Use safe mode to isolate issues with your Mac - Apple Support

Another thing to try, is to set up a new user account as a test:
How to test an issue in another user account on your Mac - Apple Support

If the issue doesn't happen in a new user, you may need to backup and reinstall macOS:
How to use Time Machine to back up or restore your Mac - Apple Support
How to reinstall macOS - Apple Support

If it's not resolved at that point, I recommend contacting Apple Support here:
Apple - Support - Product Selection

I hope that helps! Keep us posted.

Thanks for using the Apple Support Communities.

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Answer 2

MoonJ.

Community Specialist

Mar 1, 2018 3:40 PM in response to JacoboMateo

Hi Jacobo,

It sounds like you're having some trouble with adjusting the brightness on your Mac. I want to help you get that working right.

Check out the steps here for adjusting brightness settings:
Change your Mac display’s brightness - Apple Support

If you go to System Preferences > Displays > Display. Do you have Automatically adjust brightness checked? Try adjusting the brightness and checking and unchecking that to see if that gets your brightness working as expected.

Let me know if that helps.

Thanks for using the Apple Support Communities.

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Answer 3

chuck_3rd

Community Specialist

Mar 1, 2018 5:10 PM in response to JacoboMateo

Hi Jacobo,

Thanks for clarifying that for us. Let's figure this one out together.

Since it seems like your iMac isn't responding to the readings of the Ambient Light Sensor correctly, let's try to Reset the SMC:
How to reset the System Management Controller (SMC) on your Mac - Apple Support

Give that a try and let me know what happens.

Thanks for using the Apple Support Communities.

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