The crazy thing is, the mouse works great when plugged into the keyboard, but the keyboard itself does not work! I even tried plugging the mouse into the USB slot on the keyboard. I tried what seems like all combinations of plugging in the two USB cables. I did some research on the forums, and found many people suggested using BIOS for the k70s, but the unfortunate thing is that the Mk2 doesn't have a BIOS switch like the older models do. Now that I've got a big kid job and my hands feel tired after too much controller use, I decided to splurge and go all out with a XIM Apex, a Razer Naga Trinity, and a Corsair K70 RGB Mk.2! I was super excited when my keyboard came in yesterday, because it was the last piece of the puzzle! I got everything all set up, only to find that my keyboard lights up but is not responding. I have wanted a XIM since at least High School.