USB connectors

Many modern-day motherboards provide a number of USB pin headers that allow connection to USB ports mounted on the front of the system case. A header will generally contain 10 pins arranged in two rows of five. On some motherboards one or two pins may be marked as NC, for no contact. These pins a redundant. On other motherboards one pin may be missing in either one or both rows.

USB Connectors

This is not a problem, since the connection between motherboard and a pair of front-mounted USB ports will generally involve the use of only eight connectors.


You'll need to consult your motherboard to ascertain the precise pin-out positions.

Generally, these will be labelled along the following lines:

  • Power pins: A power pin on each row, labelled as Power, Vcc, or +5V.
  • Ground pins: A ground pin on each row, labelled Ground, or GND.
  • Data pins: Two plus data pins and two minus data pins, both one on each row. These are typically marked as USBD2+/USBD3+ and USBD2-/USBD3-, or USBP2+/USBP3+ and USBP2-/USBP3-, respectively.

Last Update: Mon May 12th 2003