I just bought a computer case and a powersupply, but nothing else yet. I installed the powersupply in the case, the powersupply has two fans inside, i also hooked up the case fans to the power supply. But when I turn on the power, nothing happened, the fans inside the powersupply didnt even spinning, the case fans didnt spin either. So was something wrong with my power supply ? or do i need the motherboard to make it work????