I have an intereted problem I want to post. I build a new computer, P4, 3.0 Gig with an Intel motherboard. I seems that since I took out the keyboard while it was on, it does not turn on after that. I did several testing and if I take out my ps2 mouse and keyboard and LPT1, it works fine but as soon as I put this on, it shutsdown. Have you people since this?
Maybe something shorted out when you took the keyboard out while it was powered on. I have done the same thing myself though many times and had no troubles, mainly on my laptop plugging in an external keyboard. Have you tried a different keyboard/mouse?
If you unplug or plug in a PS2 device with the computer on you're always playing with fire. It may not do anything (pretty common), it may just fry the PS2 port (I've seen this one a few times) or you can do more serious damage to the motherboard. This last one is very rare, but apparently that's what happened to you. This is why I always enable USB keyboard support in my computers' BIOS the first time I power them up. That way if something happens to the keyboard port the motherboard isn't useless. I've never understood why this option isn't on by default on any motherboard I've ever seen. I mean if you don't have a keyboard you can't enable it.