Blackwidow v4 X - function key disables lighting | Razer Insider
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Blackwidow v4 X - function key disables lighting

  • February 6, 2026
  • 1 reply
  • 11 views

dementurd

Just got the keyboard yesterday, still grasping with synapse + chroma; one main issue is the Function key doesnt seem to be working as intended (FN + CTRL 1 to 9 etc to change the rgb effects). It only disables the lighting on all keys except F9 to F12, and INS, DEL, HOME, PAGE UP, PAUSE (which are all on white color), and happens only when Function is pressed down. Once released, it goes back to the default green that I've set to the profile. 

Whats happening and how to fix this!?

1 Reply

dementurd
  • Author
  • Insider Mini
  • February 6, 2026

After further research, I realize when you press the Function key, it's supposed to light up only those few keys like F9 to F12 etc (and lights off for the rest). Ive seen this on few Youtube videos, however the difference is those videos also have both CTRL keys lit up as well, plus a number key if that RGB effect is in place. I guess this means those lit keys are active keys you can press for further function, so in this case press FN + CTRL + a number and you’ll get that RGB effect. This is very clear on this video at time 1:20 :

 

So again the bummer for me is that the CTRL key is not lit, hence I can't execute the RGB changes at all (also tested this on a new, fresh profile). I can only do FN + lit keys like increase or decrease brightness, media etc. Could it be those videos were still based on Synapse 3? As I'm using the latest firmware and Synapse 4. Or is there something wrong with my particular keyboard?

Razer Support pls comment!??