The brightness of display of my MacBook Air is fluctuating. It is getting black and bright continuously. I don't know what to do or how to resolve the issue.

  • Are you sure this is not related to your movements in front of the camera and so the sensor (which is co-located with the camera)?
    – rebatoma
    Dec 27, 2015 at 15:41
  • @Mattia Yes, it is not related to the camera. Brightness is fluctuating between 0 and selected level.
    – Suhail
    Dec 27, 2015 at 15:46
  • Therefore the problem may be solved with a restore/recover of the basic settings of the Mac.
    – rebatoma
    Dec 27, 2015 at 15:57
  • can this process delete any data.
    – Suhail
    Dec 27, 2015 at 16:00
  • To be more precise, I think the problem you have is related to some bug in the settings of the driver (maybe you instal something new and an error occur). I mean that this is not due to some sensor that are broke (hardware problem). Therefore I suggest a restart of all the system in order to replace all the drivers and correct problems in the software. This procedure may delete all the content of your HD. Save all your important documents and files before proceed.
    – rebatoma
    Dec 27, 2015 at 16:06

1 Answer 1


The first thing I would try is to disable auto brightness: System Preferences → Displays → uncheck Automatically adjust brightness.

If that doesn't work (or if it does and you still want auto brightness), try resetting the SMC (System Management Controller) — the SMC controls many hardware features of the Mac and resetting it can fix such problems.


  • The display backlight doesn't respond correctly to ambient light changes on Mac computers that have this feature.

Source: https://support.apple.com/kb/HT201295

  1. Shut down the computer and connect the power adapter.

  2. Press ⇧⌃⌥ and the power button, then release them all at the same time.

    The Mac shouldn't boot and will remain off. The LED on the MagSafe connector may change colour and/or flash briefly.

  3. With the charger still connected, press the power button to turn your Mac back on.

  • It did SMC but it does not work.
    – Suhail
    Dec 28, 2015 at 3:18

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