I installed the new power supply thins morning and the same thing is happening. I have disconnected everything in the computer so far nothing has worked. I removed the graphics card both NICs, the primary and secondary harddrives, floppy, DVD, and the memory simms one at a time and swapped simm slots just in case still no joy.
The only thing that gives any indication that power is applied is the "Aux_Pwr_LED"about in the center of the mother board. If I plug in power to the computer the Aux_Pwr_LED will illuminate and will stay that way for approximately 45 seconds to a minute due to capcitor bleed down after I remove power from the computer.
I believe whatever has caused the problem may have ruined the new power supply as soon as I installed it so I'm stuck till I figure out what's gone south.