ASROCK TRX50 WS User Manual page 42

USB 2.0 Headers
(9-pin USB_1_2) (see p.7, No. 29)
(9-pin USB_3_4) (see p.7, No. 28)
There are two headers on this motherboard. Each USB 2.0 header can support two
ports.
38
USB_1_2
USB_PWR
P-
P+
GND
DUMMY
1
GND
P+
P-
USB_PWR
USB_3_4
USB_PWR
P-
P+
GND
DUMMY
1
GND
P+
P-
USB_PWR