my hp elitebook 840 g3 keyboard lights not working even its a new laptop

[hammadddd]

help my keyboard lights not working,by pressing the fn+f5 etc. 

[Hobbit78]

I've recently solved this issue on my Pavillion Model, so hope this helps.

Enter Bios on start up.. (Usually repeatedly pressing ESC or F10)
Scroll over to SYSTEM CONFIGURATION, 

then down to ACTIVATION KEYS MODE
ensure this is listed as DISABLED
then SAVE and EXIT. 

The illumination should now work.

- It's seems counter-intuitive, but HP is looking for both FN+F5 to switch the illumination on/off. By "Enabling" the activation functions, it removes the FN input, so the lights don't work.