Pull everything off the puter except the hard drive, memory and video card. Power the puter up with the original memory stick. If nothing happens I would suggest you try to convince a friend to temporarily allow to to use their power supply to see the result. If you add another working powrer supply and are running minimal devices at boot, your mobo is probably the culprit. I'll wager that it's the PSU. It's hard to imagine that you have 4 bad mem sticks!
Noli Nothis Permittere Te Terere!!
EVGA 680i, Dual EVGA 8800GT'S (650/950), 4 gigs OCZ DDR2 1066, Intel Q9450 at 3.8 Ghz, Koolance Water Cooled, Dual Plextor16x DL DVD+/-RW. Dual WD 250gb 16mb Cache Sata 3.0. 3DMark06 score = 19,168.