I have a new laptop, Lenovo U330. I installed elementary freya 0.3.1. But the backlight does not work in my keyboard. That was working fine in Windows 8.1 before I install elementary. Is there any way to activate that? If not I would open a new issue in Launchpad ;)
Not sure about the U330, but it works fine on my Lenovo U31 running elementary OS 0.3.1 and prior to the 0.3.1 update. I think it is the F9 key that enables it on the U330. If you have Hotkey mode disabled in BIOS, you need to press Fn + F9 to turn on the backlight.
"Note:If you changed the HotKey Mode from Enabled to Disabled in the BIOS setup utility, you will need to press the Fn key in combination with the appropriate hotkey"