I recently attempted to clean out my fan, which requires removing the keyboard of my Lenovo P500 laptop to get to. Under the keyboard there are two sets of wires that connect it to the laptop: one which I assume is for all the keys since it is much wider and the other which I believe powers the keyboard's backlight. I accidentally disconnected the one which I believe powers the backlight and eventually got it back on but now when I boot my computer the backlight turns on, but the original Fn + Space keystroke to toggle the light on/off doesn't do anything so the backlight is stuck on.
I typically run linux (LMDE), but today I re-installed Windows 8.1 to see if upgrading the driver for bios or anything else solved the problem, but to no prevail.
Although getting the Fn combonation back would be ideal, I'd be just as happy if there was some script I could run (In windows or linux) to toggle the backlight.