I need to solder an external switch onto the circuit board of my laptop. I have the laptop completely dissasembled and I used a multimeter to check for continuity on the 4 points around the power button. All 4 of the points were continuous when the button was NOT depressed.

Why is this? I thought only one combination was supposed to work, not all 4 buttons at the same time! Can someone please explain this and tell me how I will be able to wire an external power button to this?