Trouble with back lit keys on ASUS laptop

I'm using an ASUS K501UX and running the latest version of windows ten. A day or so ago I turned on my laptop and the keyboard was immediately back lit. I tried using the keyboard commands (fn - f3, fn - f4) to adjust the light, but it wouldn't change. I don't really care for the back lit feature, and I would like very much to turn it off again, but the keys aren't working and I do not know how to turn them off manually elsewhere.

How do I get the keys working again? Or, alternatively: How do I turn off back lit keys manually?