OKAY people, dumping the Mobo for this, IMO, little thing, is probably unnecessary waste, unless you are itching for a new Mobo anyway.
Do you understand what this connector does? Is a simple 12V feed, that's it. It only provides 12V to the Mobo and that's all it does. 4 of those wires are ground and the other 4 are the 12V. Missing just one wire is not going to affect in a major way, I would just go without that one wire by cutting it off completely. BUT, if you want it perfect, a new Mobo$.