SpeedFan controlling CPU fan but not chassis fan? Motherboard issue?

[lilafrica14]

Ever since I bought a Biostar B75MU3+ mATX motherboard the case fan is running at a full 100% (about 2900 rpm). I decided to give Speedfan a go and was able to find a way to adjust the CPU speeds but none of the PWM settings adjust the case fan. I have all PWM modes set to software controlled and am having no luck. Is there something I'm missing? I've tried to find some threads on whether my motherboard chipset supports case fan control but I have been able to find nothing. IT8728F is what all the fans run from. Any help would be greatly appreciated!

Nathan

 

[popatim]

Whats the case fans make and model#'s?