Minibook X N100 - Keyboard backlighting not working anymore

Hello,

I have a Minibook X N100.
The backlighting of the keyboard was unsteady from the start.
Sometimes it worked, sometimes not at all.
A while ago I changed the BIOS setting to always on and afterwards it was working.
Now I have not used the laptop in a while, I started it and the keyboard stays dark. No F5 or Fn+F5 does change it.
I changed back and forth the BIOS setting with restart, no change.
Keyboard stays dark…
Any ideas what I can do?
I bought it in February this year.

Thank you
Joe