Asus P5B - Manual (Page 34)

2-0 Chapter 2: Hardware information
. Connect the CPU fan cable to the connector on the motherboard labeled
CPU_FAN.
2. Push down two fasteners at a time in
a diagonal sequence to secure the
heatsink and fan assembly in place.
B
A
A
A B
B
Do not forget to connect the CPU fan connector! Hardware monitoring errors
can occur if you fail to plug this connector.
A
B
R
P5B
P5B CPU Fan Connector
CPU_FAN
GND CPU F
AN PWR
CPU F
AN IN
CPU F
AN PWM