Actually.. If you're running BIOS 4102 or the latest 4206.. The Chip set fan by DEFAULT now is set to be OFF until PCH reaches a certain temperature...
To test, gobinto bios and set PCH fan speed manually or just select DISABLE option to have it on all the time.
NZXT Phantom 820
Asus Rampage IV Extreme
NZXT HALE90v2 1200w PSU
Intel i7 3960X OC'd @ 4.7Ghz
Corsair H100i (Push/Pull)
MSI GAMING 4G GTX 980
16GB Corsair Dominator GT 2133Mhz
2 Samsung 840 Pro 256GB SSD's (RAID-0)
2 Samsung 850 Pro 256GB SSD's (RAID-0)
SoundBlaster Z PCIe Sound Card
Logitech Z906 5.1 Surround Sound
Sennheiser PC360 Headset
LG Blu-Ray Burner
Windows 10 Professional 64-bit