Galaxy Note 4 LED not working

[AC Question]

The LED on my Note 4 doesn't work. Is there a way to test it to figure out if it's a software or hardware issue? I tried the secret menu *#0*# but that doesn't open the menu (it doesn't work on my wife's or son's phone either, maybe it's been disabled). Is there any other way to force the LED to turn on to determine if it's a hardware issue? Or are there any hidden settings that I might be missing that I need to adjust?