Studio XPS16 (1645) Media Buttons not illuminating

All the media buttons work, but I can't see where they are at all because they do not illuminate when they are touched.

I swear I thought I saw some software setting about controlling the illumination, but can't find any documentation on it.

Is it possible that the backlight died on the buttons (backlight on keyboard works fine, and I can cycle it through off, dim, normal without problems)