Asus T3-M2NC51PV - Manual (Page 54)

4-8 Chapter 3: Starting up
6. 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 Out 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.
7. 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
M2N5-BN
M2N5-BN Digital Audio Connector
+5V SPDIFOU
T
GND
SPDIF_OUT
R
M2N5-BN
M2N5-BN Internal Audio Connector
CD
(black)
Right Audio Channel
Left Audio Channel
Ground
Ground