How the reset button of a PC works

Hello, i would like to know how does th reset button on a PC work, I ask because my dad was checkin a motherboard some days ago and when he pressed the reset button it stuck pressed and the cables that go to the jumper melt and there was a little of smoke even, I know that th reset button sends a signal to the microcontrollers and the microprocessor that take all their outputs to low level and then it restarts, at least I've been told that. But how is that signal? why exactlly would it melt and release smoke when it stuck? I think, maybe the "conflict" between the stuck signal to send them to low and the oscillations of the crystal made some problem, but that's just a vague idea.

Thanks ahead of time.
Hope for some answers.

It simply grounds the reset pin, if things smoked, then it wasn't connected correctly, and almost certainly placed a short between supply and ground.

Thanks for the answer, you mean the reset pin of all the PICs? that's the signal they ment when I was told that?
maybe it wasn't connected in the right jumper.

I thought it was a signal a little more complex, i mean, being microcontrollers.
Thanks again.

Well i asked and it seems to be right connected, if it was, the fact that it stuck pressed and i mean it still doesn't come out, could cause a problem?

If everything was wired correct, and the reset line smoked the wiring, then something was wrong with the mother board.

Thanks for the answer, I will try to find out what it is.

By the way kchriste, nice signature.