the Voltage switch I'm talking about should be a little red switch on the back, that switches from standard US Household Voltage to European standards (I forget the actual numbers, but US is 100 something, & Europe is 200 something, I want to say its 115V vs 230V, but don't quote me on that)...
its possible your PSU doesn't have this on it, not all do, I have a couple that don't & some that do. but it was just a step to check in case, just rule out.