any suggestions to solve my problem?

this is my laptop keyboard  F10 with Fn is for back-light

also i have those option in uefi settings

keyboard illumination -- set to Bright

keyboard back-light timeout on AC  -- set to 10 sec

keybard back-light timeout on battery -- set to 10 sec

not work on win10

is it normally work under operating system or also must work under uefi?

i wonder i can change brightness under uefi immediately is it the same with back-light ?regardless of operating system?

plz help

Don't double-post the same problem.

This thread has been moved to the Inspiron Laptop forum.

Neither of the Inspiron 3580 models sold in the US show a backlit keyboard. First thing to verify is that your system has that option in the first place.  You will see the keyboard backlight turn on right after you power up the system.  If it does not, chances are your keyboard is not backlit.

You can also verify the keyboard type using the service tag and the Dell support site - look at the original configuration for the system. 

Note:  the BIOS option for a backlight may be there regardless of the keyboard, because boards are very often used in other models that do have a backlight option.