EVGA nForce 3 250 User Manual page 22

Headers
AUDIO: Line-Out/MIC Header for the Front Panel (9-pin)
Some case manufactures supply audio connectors built into the front of
the case. This header will allow a cable to be connected from the
motherboard to those built in connectors. This header connects to the
front panel Line-Out and the MIC.
Without the cable installed, this headers default jumper setting are 5-6
short and 9-10 short. When you install the cable, you must remove
these jumpers.
USB3/USB4: USB Port Headers (9-pin)
These headers are used for connecting an additional USB port plug. By
attaching the optional USB cable, two additional USB plugs can be
affixed to the back panel.
AUDIO
AUD _ MIC
AUD _ MIC _ BIAS
AUD _ FPOUT _ R
HP _ ON
AUD _ FPOUT _ L
Line-Out, MIC Headers
USB3
Pin 1
USB Port Headers
22
Pin 1
2
AUD _ GND
AUD _ VCC
AUD _ RET _ R
AUD _ RET _ L
9 10
USB4
Pin 1