I have Dell XPS M12010 laptop. I have replaced keyboard for new one. After this action FN key don't functioning at all. What should I do?
Welcome to the Community. Try installing Dell Quickset and see if that makes a difference. Use the below link for help.
Put the old k-board back and see if the FN key works. May be a 2nd defective k-board.
The latest version of QuickSet has been installed before this post. No any changes
Try reseating the keyboard again, if that does not work as Travis299 said it could be a defective keyboard.