there is a black cable hanging out of the power supply with connectors which connect to the power supply switch. The colours of the wires are black, brown, blue and white. The diagram indicates on the PSU that the all four connect to the same switch.
It also says on the diagram that the L (live im assuming) is switched by connecting the black and brown wires, and the N are switched by connecting the blue and white wires.
It appears that the two sets of wires are connected to each other when the power supply switch is switched on.
Unfortunately I don't have the switch - the PSU didnt come with one
Can I simply just connect up the black to the brown wire, and the blue to the white wire permanently for it to turn on or does it need a proper PSU switch?