MSI B550M-A PRO Manuel D'instructions page 12

ATX_PWR1, CPU_PWR1: Power Connectors
These connectors allow you to connect an ATX power supply.
12
1
4 3
2 1
⚠
Important
Make sure that all the power cables are securely connected to a proper ATX power
supply to ensure stable operation of the motherboard.
12
Overview of Components
24
ATX_PWR1
13
CPU_PWR1
1 +3.3V
2 +3.3V
3 Ground
4 +5V
5 Ground
6 +5V
7 Ground
8 PWR OK
9 5VSB
10 +12V
11 +12V
12 +3.3V
1 Ground
2 Ground
13 +3.3V
14 -12V
15 Ground
16 PS-ON#
17 Ground
18 Ground
19 Ground
20 Res
21 +5V
22 +5V
23 +5V
24 Ground
3 +12V
4 +12V