My Dell laptop Latitude 3590 brightness function keys stopped working

Question:

My Dell laptop Latitude 3590 brightness function keys stopped working. What should I do?

Answer:

I recently, faced this issue. Searched answer over internet. Surprisingly, one funny solution worked for me.

1. Restart your laptop
2. While its restarting, keep function key pressed and along with that keep pressing up arrow & down arrow key.
3. Login when login window shows
4. Now try changing brightness using function keys...It should work

Hope it works for you!