MSI MS-5156 Manual page 29

This type of connector already supports the remote ON/OFF function. You
don't need to connect the JRMC1. However, you need to connect the
Remote Power On/OFF switch (JRMS1 or JRMS2).
ATX Power Connector Pin Description
20
19
5V 5V
12V 5V_SB PW_OK
10
9
16
18 17
GND GND
-5V
5V
GND
8 6
7
2-23
10
1
ATX
Power Connector
13
14
15
GND
GND
PS_ON
GND
GND 5V
3
5 4
20
11
12
11
-12V 3.3V
3.3V 3.3V
2
1