|doubt it's the hard drive unless there's a dead short. if you disconn. pwr from it, you should get the bios POS/boot screen if the hd was shorting all pwr from mobd. Otherwise since all new components, might be incompatibility. does the F1/del key "dance" at boot give you bios setup? If not, probly RAM problem (not necc. bad, just problem).|
ps: what LikelyS said about ps test I agree. Usually if PS craps out you get nothing (no fans etc) at all, but that does not mean PS is ok as amp output might be insufficient to drive system complete. (one other option if you suspect this is remove ALL removable components except ram, including hard drive, and see if you got POST screen).