Fn key

Recently i can't adjust my brightness with my FN key or my volume. Everything was working perfectly but after 1 night, after i shut down my Asus laptop as always in the evening, the next morning the combo for brightness: Fn+f5/Fn+f6 and for volume Fn+11/Fn+12 wasn't working anymore. I tried all the stupid ideas from the google/ youtube to fix it but for nothing. I can't find a solution that actually works. Can somebody help me? I use those combos a lot. I need them and i dont wanna reinstall my windows only for this.
I have Asus k555l, windows 10.