Lock/Power Button STILL not working?

Hi. I recently replaced the audio and lock button cable and all of the buttons seem to work fine except for the power button itself? It is clicking more accurately compared to before. I didnt replace the lock button itself only the cable it works off. I dont understand the point in replacing the lock button itself because it is just metal and has no moving parts etc? so if i am in wrong about the button could someone please help me? i dont want to pay for a button if there is no need for it. P.S. if the button does affect it then why is it my lock button still wont work? Thanks in advance.