Asus T4-M3N8200 - Manual (Page 51)

4-9 ASUS T-Series M3N8200
6. Optical drive audio connector (4-pin CD)
These connectors allow you to receive stereo audio input from sound sources
such as a CD-ROM, TV tuner, or MPEG card.
R
M3N18L
M3N18L Internal Audio Connector
CD
(black)
Right
Audio Channel
Lef
tA
udio Channel
Ground Ground