ORIGINAL: bgosselin
It is odd that the PCB has three 12v outputs labeled, but specifies only two on the outer case label.
I probably should go look at the ATX spec, but I assume the red/brown connection consists of the 5v line and the 5v sense wire tied together?
I agree WRT to the three 12v outputs.
I think he meant orange/brown for his 3.3v to sense wire connection.
On your motherboard connector, do you have any pins other than orange that have a second wire? Most supplies have only a 3.3v sense wire, but I have seen a few that have sense wires for other rails.