It all started with the fact that once the button is not working Fn +, combined with all the keys. Next, I clicked off the keyboard backlight and subsequently turn on the backlight keyboard failed. The keyboard backlight turns on only when the notebook.
I reinstalled the operating system, installed all the drivers, but a positive result was not achieved.
Advise what could be done? How can you test the Fn button? I tried the game assign Fn button on certain weapons, but it has no reaction. Should it be?