Dell Dimension 2400 - Manual (Page 40)

DC Power Connector P2
DC Power Connectors P3, P5, P6, P8 and P9
DC Power Connector P4
DC Power Connector P7
20 +5 VDC Red
*Use 22-AWG wire instead of 18-AWG wire.
Pin Number Signal Name 18-AWG Wire
1 COM Black
2 COM Black
3 +12 VDC Yellow
4 +12 VDC Yellow
Pin Number Signal Name 18-AWG Wire
1 +12 VDC Yellow
2 COM Black
3 COM Black
4 +5 VDC Red
Pin Number Signal Name 22-AWG Wire
1 - No connect
2 COM Black
3 COM Black
4 +3.3 VDC Orange
5 +5VDC Red
6 +12VDC Yellow