I was recently tinkering with my system and when it came to pressing the power on button nothing happened. I opened up the case and the green light on the mobo was on so I knew power was getting there. I assumed it was a power switch issue so I shorted out the power switch pins on the mobo and all was well. More recently I am getting the same problem but now shorting out the switch doesn't work. This morning she refused to power up so I laid it on its side, opened it up, pressed the switch a few times and swore at it. Nothing happened. SO I am just sitting there conjuring up new swear words when it just starts up, fans spinning and away we go - I never even touched it. I have restarted a number of times today and no problem. I'm afraid to power off for an extended time, but I live in Houston and this puppy puts out a fair amount of heat and we don't need any more heat in the house! So it doesnt seem to me that it could be a PSU problem? While running, voltages are stable etc. So is it a mobo problem? It seems after an extended shutdown (i.e. overnight) it cools down and then won't start. Is that a symptom of something cracked? I don't mind replacing parts - I just don't know which parts or how to troubleshoot this problem. Any suggestions?