Compaq 320, 321, 420, 421, 620 and 621 Notebook PC and HP 420 and 620 Notebook PC

8 Connector pin assignments
Audio-in (microphone)
Pin Signal
1 Audio signal in
2 Audio signal in
3Ground
Audio-out (headphone)
Pin Signal
1 Audio out, left channel
2 Audio out, right channel
3Ground
148 Chapter 8 Connector pin assignments