Sorry, but I can't answer your question. This is my first desktop. The machine is pre-built, and below is a list of components. I installed HWinfo, but the only fans there were the CPU and GPU?Do you only have them connected to the cha_fan headers?
Either, can you take a pic of your motherboard showing the fan connections and post it through imgur.com, or take a look inside to where the fans wiring cables connect to, that are not showing in the bios