Asus T4-M3N8200 - Manual (Page 50)

4-8 Chapter 4: Motherboard Info
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
R
M3N18L
M3N18L Digital Audio Connector
+5
V
SPDIFOU
T
GN
D
SPDIF_OUT
7. Digital audio connector (4-1 pin SPDIF_OUT)
This connector is for an additional Sony/Philips Digital Interface (S/PDIF)
port(s). Connect the S/PDIF module cable to this connector, then install the
module to a slot opening at the back of the system chassis.
The S/PDIF module is purchased separately.