G5 Mac won't boot...fried?

Hi, wonder if anyone can throw suggestions as to why my 3year old 1.8ghtz G5 is showing little signs of life.

Went to power up through front button, white led lit up then heard a click (like that when shutting down) and light went out immediately. repeated this sequence several times, then smelt a faint but ominous acrid burning smell; needless to say I didn't try booting again. Has anyone any ideas/similar experience of this this, sounds (and smells!) like it might be serious. Help!

Oh, just in case it matters, the power supply was switched off the other day whilst the Mac was up and running - don't know if that may have damaged something...


Thanks in advance
si

did you reset the PMU? Usually a button on the motherboard you'll press to reset by pushing ONCE. As far as the smell, yikes! Let us know how it works out.