Building a PC is relatively easy, just so happens you have seemingly got a faulty motherboard. Don't let that put you off from building more.
Did you explain to SCAN the exact scenario of how the system was setup for the fan on the CPU not to spin when plugged into the CPU Fan Header? Also, did you take note of the serial numbers of the parts you routed back?
Oh and when you do build, I've learnt over the years...build a PC slowly and outside the case; once you know all the core components work (mobo, ram, cpu, gfx), build it in the case.
If you could, I'd like to see some pictures too...