I´ve bought a case with 450w power supply, it worked for a while, just clocked my cpu as 11*166, low cas on memory, and ti4400@ti4600, and opened 3dmark2001, when the opening screen just started the system turned off, and the power was gone. After that, changed to my old(very old) 300w, and everything worked fine again, even overclocked. There are 5fans, 1for case, 1 for chipset, 1 for cpu(volcano9), 1 for the video card, and the original from the power supply, but the old 300w hold it very well.
I don´t think that i´d smoked the 450w, or it´s fuse, because it still got the green light working at a7v333, maybe it´s an undecover 250w.. what could it be?