Dual G4 Quicksilver Won't Start


My tech level is average.

My Dual 1GHz G4 Quicksilver 2002 was asleep when the house power went off. It was off for around 5 minutes. After the power returned, I attempted to start the Mac using the keyboard, but there was no response at all. I then tried the machine's Power button, with same result. (When depressing the power button, it illuminates, but then fades-away when released.)

Things to note:
the machine is not configured to auto re-start after a power loss.
the surge protector is undamaged and had not been 'triggered'.

My questions are these:
What is the likely failure here?
If the power supply is dead, would the start button illuminate when depressed?

Any information/suggestions you have to offer about this would be helpful & appreciated.