MBP, cant get keyboard backlight functions to work

I'm not sure why they're a difference between your Macs, but this should do the trick for controlling the backlight sans ambient light http://labtick.proculo.de/

 

No idea. My POS CD MBP has recently started offering me the option - sometimes. I can at times adjust my backlight, this is even with lab tick not running. But at other times I can't and get that stop sign. My newer C2D MBP has never offered me the option, always with the stop sign.

If you ever find out, do let us know.

 

I believe the symbol means a setting is wrong...

 

Same issue here...

I've got the same issue here. My MBP keyboard backlight used to work perfectly until a few days back and now the F9 & F10 keys don't work (i.e. manually activate the backlight).

Would appreciate any help on this matter.

Thanks.

 

I have a similar issue with a 2 week old MBP 2.16 c2d 15". The F8 F9 & F10 keys stopped working about two days ago. If I partially cover the speaker grills the screen dims but the F-Keys remain inactive as described in other posts. I have found that by completely covering the speaker grills so that no light is able to get in then the F-keys sometimes become active – at these times pressing the F9/F10 key turns the lights off and the display has the ‘stop sign’.
I have managed to get the automatic lighting to work again by fiddling with the F-keys in a blacked out room but it is intermittent and I quickly loose it again Once I got the manual control working, but only once and I don’t know how.
With no solution in sight this machine is going to the repair shop – unless of course someone can tell me what I need to do to fix it myself.

 

Okay, this is an ancient thread, but I'm having the same problem - any solutions?

 

Which problem are you referring to