Keyboard only "shift", "windows" and "Alt" key work

Hi, I installed arch with kde recently and would like to use it, but my main keyboard doesnt work.

the only keys which are working on the "broken" are "windows" "shift" and "alt". and I am currently using another crappy keyboard. My "broken" keyboard is listed as a device under the mouse-settings and both keyboards work fine under windows on the same machine (dual-boot).

The broken keyboard is a corsair K70.