There is a one.35mm DC port for an external power source but its connected on to the 5V line so if you have to externally power, we suggest prying open the situation and reducing the pink 5V line in the USB https://marctjkw838140.blogthisbiz.com/34568745/5-essential-elements-for-iogear-2-port-usb-2-0-automatic-printer-switch