Page 2 - All fans spin but NO POST

Working on a hunch here in regards to it not booting. Look at the capacitors around the cpu. Specifically the tops of them. Do you see any corrosion or bulging? And/or next time it does not boot, unplug it from the wall and press the power button repeatedly (pausing 1 second each time) about 10 times. Plug it in and power it up. Does it work now?

That aside, the temperature can be greatly affected by the thermal compound (or lack there-of) used on the processor. I had a similar problem some time ago when in a moment of utter stupidity I replaced the heat sink without replacing the compound. Well it would boot fine but doing almost anything would make the temp jump up like mad and the variable fans would kick into high gear. Pulled it back off, used a little compund and now the problem is gone (of course).