Asus PREMIUM P5N72-T User Manual page 60

7. Chassis intrusion connector (4-1 pin CHASSIS)
This connector is for a chassis-mounted intrusion detection sensor or switch.
Connect one end of the chassis intrusion sensor or switch cable to this
connector. The chassis intrusion sensor or switch sends a high-level signal to
this connector when a chassis component is removed or replaced. The signal
is then generated as a chassis intrusion event.
By default, the pin labeled "Chassis Signal" and "Ground" are shorted with
a jumper cap. Remove the jumper caps only when you intend to use the
chassis intrusion detection feature.
8. Digital audio connector (4-1 pin SPDIF_OUT for ASUS HDMI VGA card)
This connector is for an additional Sony/Philips Digital Interface (S/PDIF)
port(s). If you are using an ASUS HDMI-equipped graphics card, connect the
HDMI card to this connector with a S/PDIF Out cable.
The ASUS HDMI-equipped graphics card and the S/PDIF Out cable are
purchased separately.
2-34 Chapter 2: Hardware information