Unplug the AC from the pc.Unplug all the HDs , DVds everything cept for the power going to the mainboard, remove all non essential cards . If the mainboard has onboard video use that and remove your video card. . Remove your ram, DO NOT put the ram back in. Plug in the pc, Turn on the pc, a normal working pc will complain that it can not find any ram and start beeping. If no beeps and no lights on the front. Go to comp usa or simular store and buy a $25 PSU tester.