~Somewhere, over the rainbow~
My understanding by a search on the internet, is that the HP XW4600, uses a version of an Intel X38 motherboard, and has the ID numbers - model fmb-0702 - on it, as well as - e93839 -http://h30499.www3.hp.com/t5/Workstations-z-series-xw-series/XW4600-Motherboard-Control-Panel-Schematic/td-p/1007169
7th post down, - jondvd - 09-28-2008http://www.ebay.com/itm/HP-XW4600-Motherboard-441449-001-441418-001-/360653087990?pt=Motherboards&hash=item53f89964f6
If this holds to be true, the BLUE header, below the CMOS battery, and close to the outside edge of the motherboard, is ONE USB header.
The Yellow header to the right of it, is the Front Panel USB header.
EACH USB header has contact pins on it, for TWO USB ports.
Does not matter which USB header we are talking about here, on that motherboard.
To identify the pinout, look for the missing pin in the header.
This is the KEY pin. http://www.motherboardpoint.com/front-usb-pinout-compaq-evo-d310-t153627.htmlhttp://pinouts.ws/usb-pinout.html