Gigabyte GA-8IR2003 User Manual page 21

1) ATX_12V (+12V Power Connector)
This connector (ATX_12V) supplies the CPU operation voltage (Vcore).
If this "ATX_12V connector" is not connected, system cannot boot.
2) ATX (ATX Power)
AC power cord should only be connected to your power supply unit after ATX power cable and
other related devices are firmly connected to the mainboard.
Pin No.
2
1
3
4
Pin No.
10 20
1 11
- 17 - Hardware Installation Process
Definition
1 GND
2 GND
3 +12V
4 +12V
Definition
1 3.3V
2 3.3V
3 GND
4 VCC
5 GND
6 VCC
7 GND
8 Power Good
9
5V SB (stand by +5V)
10 +12V
11 3.3V
12 -12V
13 GND
14 PS_ON(soft on/off)
15 GND
16 GND
17 GND
18 -5V
19 VCC
20 VCC