Did you recently do any upgrades on the device? Like from say 8.0 to 8.1? If so, that may be your problem.
If that is the case, then you may need to update the drivers on the device, as sometimes it doesn't work correctly when making that change.
If the driver update doesn't fix it, then you may have to revert to the original system OS and then upgrade to 8.1 again. (or 10 if that is what was upgraded to)
A Side Note: The light being on has no real effect on your access, or if things work or not, it just can be annoying to see (if you are like me that is. It would bug me to see it on when doesn't need to be. LOL)