Some HP business class desktops use a proprietary Power Supply with (2) 6 pin connectors This PCB allows you to cut off the connectors from your current power supply and use a standard 24-pin ATX power supply you still need a small 5v to 12v boost converter which can be found on ebay Note: I had to use a 3-wire fan instead of a 4-wire fan to get rid of the [NO Power Supply Fan] warnings 6 Month update: Board works flawlessly, I had the boards made by JLCPCB in black matte looks a lot better than the one I home etched but same functionality albeit slightly smaller I salvaged my connectors from an old motherboard and the 5V convertor came from ebay This is the same design as I got but any 5v -> 12v output boost convertor should work There isn't a very high current draw.. its only for standby power https://i.ebayimg.com/images/g/jKoAAOSwqMRa3dbY/s-l500.jpg