Asus SABERTOOTH X79 - Manual (Page 52)

2-34 Chapter 2: Hardware information
Chapter 2
4. Place the fan cable into the cable slot
on the rear I/O cover.
5. Connect the fan cable to the
ASST_FAN connector on the
motherboard.
6. The PCH cover is pre-assembled with
a slim-type fan, providing effective
heat dissipation to the PCH. Remove
the protection film on the PCH cover
before use.
If the PCH fan is not working or
the fan speed is too slow, check if
the fan cable is well-connected. If
the problem persists, refer to local
ASUS service centers for help.