Well Best Buy confirmed the correct voltages and I can report that the paperclip test is not fool-proof
I had even performed it with a second set of eyes.... can say with metaphysical certitude that the switch was in the ON position. But, the unit must have been upside down and I was assuming that I would be able to hear the fan. It is nearly completely silent.
So now that I know that the PSU is working, the motherboard seems to be cooked. Isn't the next logical step to replace the motherboard? I can find the neccesary model on ebay for about $110.