2008 iMac 8,1 still won't power up after replacing power supply

A few days ago my iMac powered-ON as usual at 8AM and was working normally, I checked email and left for a meeting. When I returned 30 minutes later my office had a slight odor of hot bakelite and the screen was dark, instead of displaying the screen saver. Thinking the power may have blinked, I pushed the start button on the back and nothing happened, tried several more times, then depressing and holding, still nothing - absolutely lifeless.
Presumed it was probably the power supply, so took it into the Genius Bar and my suspicion was confirmed; they checked the LEDs and advised that the power supply was mostly bad. Despite the hassle, the solution seemed simple enough: replace the power supply and I'd be back in business. That proved to be wrong!
Bought a new (NIB) power supply from a reputable dealer and carefully disassembled/reassembled the iMac feeling ever so confident that I'd hear the chime and fan whir when I depressed the ON/OFF Button. To my total disbelief nothing has changed! Its still dark and lifeless as before. Not discounting a theoretical chance that both power supplies could be bad I'm puzzled what to do next and where to look. Obviously, there isn't much in line ahead of the power supply, but given the fact there is no fan noise and no glimmer on the display, I can't fathom it could be anything other than something between the power cord and the power supply.
What could have caused the hot bakelite smell? The original power supply had NO bakelite odor and no burned chips, traces, scorched transformer windings or cooked capacitors. That had surprised me, so sniffed around the motherboard/backplane and detected a slight bakelite odor at or near the hard drive; I haven't cracked the case yet to examine the HDD - but, even if it were dead, I'd still hear the chime and fan, and maybe see at least a slight glow on the display, right?
And so, I'm calling on all you "pros from Dover" for some insights, wisdom and pointers to help me diagnose the problem and get the thing fixed. Your thoughts?
Thanks, much, compadres. AK

My assumption is the same as KT’s, the logic board fried. If the logic board is functional, even if the hard drive is dead, it should power on and perform the POST. Since it isn’t my advice is the same as KT’s - hope you don’t need Snow Leopard to run some older program(s).

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