Power button cable doesn't fit on new motherboard

That is a good find Phone Man.

Almost all motherboard front header panels are labeled, it shows quite clearly what pins go where, and mark where the positive and the negative pins go. And Bob already gave you a pic of what the end of all the front power connectors look like, you simply match the right wire to it`s connector on the motherboard header and put the positive and negative terminals on the pins exactly the same way. In the picture of the motherboard on the left, the speaker plug would cover the 4 orange pins on the top right of all those pins, with the positive lead (red) plugged in all the way to the left of the 4 orange pins. You can see the last orange pin to the left has a cross at the bottom to signal a positive connection. And all the black plugs there in the bottom picture are labeled with a + or -

It`s a piece of cake, Vanilla cake

welcome to the world of computers!! wait till you have a gpu go up in smoke or a stick of ram melt.. these are curve balls and expensive ones at that ^_^