Asus P5A-B User Manual page 27

III. INSTALLATION
5. CPU Cooling Fan Connectors (FAN, 3 pins)
This connector supports a 3-pin CPU cooling fan of 500mA (6W) or less with a
minimum of 3,500RPM. Depending on the fan manufacturer, the wiring and
plug may be different. The red wire should be Positive, the black should be
Ground, and the yellow wire should be Rotation signal.
WARNING! The CPU and/or motherboard will overheat if there is no airflow
across the CPU. Damage may occur to the motherboard and/or the CPU fan if
these pins are incorrectly used. These are not jumpers, do not place jumper
caps over these pins.
P5A-B Power Supply, CPU, Chassis Fan Power
6. Chassis Intrusion Alarm Lead (4-1 pin CHASIS)
This requires an external detection mechanism such as a chassis intrusion moni-
tor/sensor or microswitch. The sensor is triggered when a high level signal is
sent to the CHASIS lead. This occurs when the side panel is opened or drive bay
doors are opened.
NOTE: When the chassis is opened, connect/short the Chassis Signal pin to the
+5VSB pin. When the chassis is closed, connect/short the Chassis Signal pin to
the Ground pin.
P5A-B Chassis Open Alarm Lead
Power Supply Fan
Ground
+12 Volt
Rotation
Chassis Fan Power
CPU Fan Power
+5Volt (Power Supply Stand By)
Chassis Signal
Ground
ASUS P5A-B User's Manual 27