FN+ESC button not working.

My volume buttons weren't working so I was looking through some forums to find out how to fix it. One of the solutions was by pressing FN+ESC to unlock them. It did not work, and I have no idea what to do. Other ones told me to press other buttons, which I did, and it still didn't work. I have an Inspiron 14 5000 laptop. I do not have a num lock button, which is something that seemed to help a lot of people. Please help me.