ReadyNAS Pro Pioneer Edition USB Connection

Hi,

I bought the non working ReadyNas chassis a couple of years ago. It started working when I removed the USB connection from the motherboard and is now running sucessfully with four WD 4T EFRX's. I don't want to risk damage by trying all the possible connections the internal USB plug would fit, so could someone advise me which are the correct pins on the mother board?

Thanks in advance,

Pete