At work right now but it's like the pic above without the camera button being back lit. It's the only one.Can you post a photo of it not lit? Is it the only one?
Quoting for emphasis. It should be backlit when the lights are on. If the lights are set on Automatic, the backlit function won't be on during the daytime.If one is out, I’m assuming the whole bank would be out. They usually aren’t individual bulbs per button.
Are you sure your headlights are turned on?