A while ago, my computer "sort of" stopped working.
It stopped turning on immediately, by which I mean, in order to turn it on you have to press the power button, make sure that the "Power on" LED isn't
illuminated, and then wait about 10 minutes for it to start up.
During these ten minutes, it makes no sounds or beeps whatsoever. Once it starts, it does everything normally: Fans start, OS boots etc.
Imagine booting your ordinary computer, by pressing the power switch, but put a 10 minute gap of nothing in between pressing the switch and the computer booting up.
I'm planning to replace this machine anyway, but out of curiosity: Is there any chance this is anything OTHER than the power supply?
Also, does anyone have an explanation for why it's happening, exactly?
My computer is connected to a voltage regulator, which I turn off when I'm not using the computer. If I power on my computer after it's been "disconnected" from the power source, it will take about 5 seconds to actually start up, just like you mentioned, it won't do anything for those 5 seconds. If I turn it off but don't turn off the regulator, it will always turn on immediately.
This only happens when I have my overclock settings active. So, it seems to be some sort of BIOS feature on this specific motherboard (Biostar i45). So what I'm saying is that it might also be something on your motherboard not working right.