Asus M3N WS - Manual (Page 55)

ASUS M3N WS 2-31
6. CPU, chassis, and power fan connectors (4-pin CPU_FAN; 3-pin
CHA_FAN1-2; 3-pin PWR_FAN)
The fan connectors support cooling fans of 350 mA~2000 mA (24 W max.)
or a total of 1 A~7 A (84 W max.) at +12V. Connect the fan cables to the fan
connectors on the motherboard, making sure that the black wire of each
cable matches the ground pin of the connector.
Do not forget to connect the fan cables to the fan connectors. Insufficient air
flow inside the system may damage the motherboard components. These are
not jumpers! Do not place jumper caps on the fan connectors!
Only the CPU_FAN and CHA_FAN1-2 connectors support the ASUS Q FAN2
feature.