Um this board pulls 45 watts max, how could that be enough to "smoke" a 400 watt psu? I'd say there's something wrong with the psu or you have something wired incorrectly (like a short). Electrical devices only pull as much power as they need -- you can hook up a 1000 watt psu to this board and it'll pull the same amount of amps as with a 100 watt psu.