Motherboard or fan issue?

[krazy_olie]

Hello,

Recently installed an Asus Maximus impact vii in to a Silverstone rvz01 and I've tried to control the fan speed to no avail. One fan is dead and I'm trying to chase that up with scan.. the other runs but at full speed and is rather loud.

Both the Asus bios and software run a sort of optimisation thing to check possible fan speeds but it keeps seeing the minimum duty cycle for the case fan as 100%. The asus fan xpert software shows 0% duty cycle running at ~1600rpm which makes no sense.
Have I missed a trick here or is something not right?

Does anyone have a recommended voltage switch/adapter they could recommend as a workaround? The zalman fanmate looks useful but too long.

edit: first channel header controls it just fine.