Manhattan External Sound Card (Model: 151429)
When I connect Corsair K70 Mechanical Keyboard with a laptop and backlight is on, it makes annoying buzzing into microphone. I tried to fix this it by changing the microphone settings, but it didn't help. When the backlight is off, it's okay, but a brighter backlight is a stronger buzzing noise it makes into the microphone. I couldn't make skype calls when the backlight was on.
Solution was to use an external sound card. I wanted cheap one, less than €10 and ordered Manhattan Hi-Speed USB 3D 7.1 Sound Adapter (Model Number: 151429). It's probably adapter made in China, selling under different "brands", I think that "AXAGO ADA-20" is the same adapter. I have plugged it into the laptop, drivers found automatically and it started working immediately (I didn't use CD from a package), but I still could hear the noise. I tried different USB ports on the laptop, USB cable extension, nothing helped. Last option, connect it with USB hub (with external power) and hurray - no noise! I use it now only for microphone. Speakers are still connected with the laptop. It's not exactly how I wanted to connect it, but input from microphone is now very clear, so problem fixed :)