@Cetlysm Thank you so much. I noticed my K70 RGB LUX has developed two bad led's. I haven't had CUE 2.18.81 installed since 2017. I took a shot at iCUE 3.26.95 to try fixing, flashed firmware I think to 3.18 and it caused keyboard to be no longer detected by motherboard during post/boot. What's really sad, is Corsair doesn't retain version history and legacy software and firmware, only after timely research I found your solution.