Keyboard Backlight not working!!!!

Have you tried turning the keyboard brightness up (I know it sounds silly) because it may have been the ambient light sensor which turned it down automatically or maybe you just can't see it with other light in the room. If this isn't the case try this: http://reviews.cnet.com/8301-13727_7-57363143-263/troubleshooting-keyboard-backl ights-on-macbook-systems/

Hope this helps,

- Daniel 

Reset SMC. http://support.apple.com/kb/HT3964

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

Best.

I have the same problem on my retina macbook, I've tried resetting smc ,pram nvram all that happy stuff still nothing.

Could it be a hardware problem?

Any other ideas?

Thanks,

Yes I have this problem and I have done a SMC reset. I will be taking my MBPr 15" into an Apple Store for a Genius bar appointemnt along with the words "Please sort this out" or words to that effect. MBPr 15" have a great dsiplay but I have had way too many hardware failures (this is my 3rd different machine and even this had to have the logic board replaced. I cannot fault the service etc. but the hardware design seems challenged.

Thanks, Daniel. Just needed turning up!