Cpu_Fan1, Pump_Fan1, Sys_Fan1~4: Fan Connectors; Jcom1: Serial Port Connector - MSI B450 GAMING PLUS Quick Start Manual

CPU_FAN1, PUMP_FAN1, SYS_FAN1~4: 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.
34
Overview of Components
Default PWM Mode fan connectors
CPU_FAN1
Default DC Mode fan connectors
SYS_FAN1/ SYS_FAN2
2 +12V
4 Speed Control Signal
1
3
5
7
9
1
1
SYS_FAN3/ SYS_FAN4
DC Mode pin definition
1 Ground
3 Sense
2
1
DCD
SOUT
Ground
RTS
RI
1
PUMP_FAN1
1
2 Voltage Control
4 NC
10
9
2 SIN
4 DTR
6 DSR
8 CTS
10 No Pin