I have a recently built PC with Z170 mobo and 6700k/980Ti and a Corsair Strafe (backlit) keyboard. I had some issues with the Ethernet interface not appearing anywhere, which I solved like other people with the same specs on Ubuntu 14.04.
After I boot on Ubuntu, it takes 2-3 minutes for the keyboard to start responding. Also, if I try to adjust its brightness, it will stop responding again. I have no idea where to start looking, since I can't find similar problems online. I have a 750 Watt supply, so I don't think it has to do with high power needs.
Note: The problem with the keyboard existed from the beginning..along with the ethernet thing
UPDATE: I bought a Razer Deathadder and it also takes the same amount of time to start working on boot.
uname -r) If it's lower than 4.4 you could try to boot a 16.04 live CD/DVD/USB-stick and see if it works there. Doesdmesg | tailshow anything related to USB/keyboard or so after the keyboard starts responding? (dmesgshows the kernel messages and is usually a good place to start looking :-) ) – Kai May 11 '16 at 16:28Also, I remember trying out 16.04 before and had the same issue. Thanks :D
– kalfasyan May 11 '16 at 16:43