SOYO SY-D6IBA User's Manual & Technical Reference page 22

Hardware Setup
To avoid damage to the system, install according to the following pin
assignment:
Slot1 #1 CPU Cooling Fan
FAN 1 Pin Assignment
GND 12V
1
2. Chassis Cooling Fan (FAN 3)
Some chassis also feature a cooling fan. This Motherboard features
a FAN 3 connector to provide 12V power to the chassis fan. Connect
the cable from the chassis fan to the 3-pin connector labeled FAN 3.
Install according to the following pin assignment:
Note: FAN 1 and FAN2 must be installed for this Motherboard,
CHAFAN is optional.
SENSOR
2 3
Chassis Cooling Fan
FAN 3 Pin Assignment
GND
Slot1 #2 CPU Cooling Fan
FAN 2 Pin Assignment
GND
12V SENSOR
1 2 3
19
SY-D6IBA
12V SENSOR
1 2 3