Dell Vostro 420 (Late 2008) - Manual (Page 114)

114
Power Supply
DC Power Connectors P3, P4, P5, P6, P7, and P8
DC Power Connector P9
2 GND Black
3 +12 VADC Yellow
4 +12 VADC Yellow
Pin Number Signal name 18-AWG Wire
1 +3.3 VDC Orange
2 GND Black
3 +5 VDC Red
4 GND Black
5 +12 VBDC White
Pin Number Signal Name 22-AWG Wire
1 +5 VDC Red
2 GND Black
3 GND Black
4 +12 VADC Yellow
Pin Number Signal Name 18-AWG Wire
4 3 2 1