Unless it's a laptop, or some other kind of specialty/proprietary power interface, one power cable is essentially the same as the next. I have to say though, 600W seems a bit light for a system like yours.

Still, if it's new, why bother trying to figure it out? Make it Cyberpowerpc's problem to fix. If they can't fix it they can give you a refund and you can take your money to someone else who can build a reliable system for you.