How to lower laptop display brightness

TOSHIBA Satellite A45 laptop and having trouble with the screen brightness
but I can't seem to get it down... the control keys are F6 to lower and F7
to increase which combined with the "FN" key should work (as far as I know),
but they don't do a thing, the computer is a bit old but seems in great
general condition so I doubt the keys themselves don't work, the
video/graphics are strong and sharp, it doesn't make a difference if on
power or battery. What do you folks think? wrong key combination, sequence
or what else? Can't find information on the net for that model. Any
suggestions?

I would really appreciate some help.

Thanks