I'd like to test a PSU using the paper clip method connecting the green wire with one of the black ones, but I wonder if I can power it on, without applying a load, or if this could damage it.
Damage a PSU if I test it without applying it a load
power supply
Best Answer
A properly-functioning consumer PC power supply should not be damaged by turning it on without a load. It should regulate the voltages on the various outputs to the proper levels (so you could measure them with a meter) but there won't be any current.