If I plug my power supply on and flip on the power switch, should the fan of the PSU start working? I'm building a computer and I was testing multiple fans on a power supply. I got nothing. So, I took it out, plugged it in, and turned it on, just to see if there was any indication of any activity, and there is no fan movement at all within the PSU and no indication to me that it is working. Should the fan start up immediately, or does it start up after a bit?