alpenglo wrote:
Thanks, but all that option does is adjust the brightness of the backlight, maximizing it in a bright room or sunlight (which is ridiculous, in my opinion) and dimming it in a dark room. With that option selected you have to manually turn the backlight off if you don't want it running at full power in a bright room, leaving you with no backlight the next time you're in darkness. That's the problem in a nutshell.
This is what I see in bright ambient room light, the automatic keyboard backlight shuts itself off. Possibly your room light is not as bright as you suspect— in this case you can test with a bright torch aimed at the FaceTime Camera/light sensor as a direct test.
Try resetting the SMC http://support.apple.com/kb/ht3964
if no resolve:
Call Customer Support (800) MY–APPLE (800–692–7753)
or on line https://getsupport.apple.com/
or call AppleCare Support at 1-800-APLCARE (800-275-2273)