I had exacty the same issue, Orange light glowing for several days and wouldnt go off whatever I tried.
I tried pressing the Fn button then the F8 button, as recommend - no change, I still had the Orange light glowing.
Then - more by accident than design - I pressed both keys Fn & F8 AT EXACTLY THE SAME TIME - and Bingo!
The light went off!
I hope this helps someone with the same frustrating issue and avoids the need for more drastic solutions.
