3 Replies Latest reply: Mar 16, 2009 5:02 PM by neuroanatomist
Ben Mortimer Level 1 Level 1

Until a few days ago I could control my keyboard's backlight using the F5 & F6 keys irrespective of the ambient light of the room I happened to be in. In the same way that I can control the screen's brightness using F1 & F2, and the sound volume using F11 & F12 regardless of the ambient noise of the room I happen to be in.

Now, when I try and adjust the keyboard backlight using F5 & F6, I get the grey box with the icon, but then instead of controlling the backlight I get an O with a / through it.

nb. When the Macbook decides that the room I am in is dark enough, using it's own light sensors, I am still allowed to have the backlight. So it does work, but as of a few days ago it is no longer under my control.

Please would someone let me know how to fix this. BTW I know that there is some software called Lab Tick that apparently gets around this. But on principle I'm not interested in installing 3rd party software, funded by donations, to fix something that should be handled by Apple, who are rather well funded by us.

Kind regards,


MacBook Pro, Mac OS X (10.5.6), MacBookPro4,1 OSX 10.5.6
  • Travis A. Level 6 Level 6
    Hi Ben,

    The ability to adjust the keyboard backlight depends on the amount of ambient light hitting the light sensor. If you're in a bright room during the day with plenty of windows, the keyboard backlight keys won't work. If you cover up the light sensor next to the iSight camera with your hand, the keyboard backlight keys will work. This is just the way the computer is designed right now...

  • Jay Hill Level 1 Level 1
    I had the same problem and took the laptop into a dark closet and dimmed the display down to the lowest level above complete black. No keyboard backlight. There are a number of posts on the web at MacRumors and other sites that also talk about this problem.

    I get the same issue, the "no" indicator when using the function keys to try and get the backlight to work. So, I downloaded Lab Tick which allows me to at least get the backlight working but the function keys do nothing and the ambient sensor doesn't do anything at all.

    Looks like it's time to go to the Apple Store and get them to fix it since it's still under warranty.
  • neuroanatomist Level 7 Level 7