CPU_FAN1, SYS_FAN1~2: Fan Connectors
Fan connectors can be classified as PWM (Pulse Width Modulation) Mode or DC Mode.
PWM Mode fan connectors provide constant 12V output and adjust fan speed with
speed control signal. DC Mode fan connectors control fan speed by changing voltage.
When you plug a 3-pin (Non-PWM) fan to a fan connector in PWM mode, the fan speed
will always maintain at 100%, which might create a lot of noise. You can follow the
instruction below to adjust the fan connector to PWM or DC Mode. However, with auto-
detection mode fan connectors, the system will auto detect the fan mode.
Pin definition of fan connectors
PWM Mode pin definition
1
Ground
3
Sense
Important
You can switch between PWM mode and DC mode and adjust fan speed in BIOS >
y
HARDWARE MONITOR.
Make sure fans are working properly after switching the PWM/ DC mode.
y
JCOM1: Serial Port Connector
This connector allows you to connect the optional serial port with bracket.
18
Overview of Components
Default PWM Mode fan connectors
Default DC Mode fan connectors
2
+12V
4
Speed Control Signal
1
3
5
7
9
1
CPU_FAN1
1
SYS_FAN1/ SYS_FAN2
DC Mode pin definition
1
Ground
3
Sense
2
10
1
DCD
2
SOUT
4
Ground
6
RTS
8
RI
10
2
Voltage Control
4
NC
9
SIN
DTR
DSR
CTS
No Pin