On Macbook Pro, F5 and F6 seems to be the "keyboard illumination keys".

However, the keyboard's illumination doesn't seem to change at all after pressing those keys.

Also, I noticed a small "no entry" sign whenever I hit those keys, how do we fix these problems?

1 Answer 1


The laptop makes note of ambient lighting and disables keyboard backlight when it's not dark. This is similar to the automatic display brightness system. Both are there to save power.

Your keyboard backlight should work in a dark room or if you cover your iSight camera so the laptop thinks it's dark.

  • heys cool, btw where's the sensor?
    – Pacerier
    Apr 29, 2011 at 9:52
  • 3
    @Pacerier: I think it's right next to the web camera. (So blocking the webcam makes the computer think it's dark) Apr 29, 2011 at 12:37
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    on my 2008 mac book pro 17", the system is quite slow to respond. After covering up the camera and / or switching off the option in system preferences to automatically dim the backlight, I actually had to wait around a minute (!) before the f5 and f6 keys came back to life. I had a lot going on with the computer, but still it was a bit surprising to have to wait so long.
    – Reb.Cabin
    Jul 12, 2013 at 22:52

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