OK youre all close but just off a hair. It's quite simple as it is the wire that connects to the power switch
that's your problem. I just fix this issue and I'm writing this post from said laptop. There is a 2 wire lead connected from the motherboard
to the switch board, it either gets pulled out from the switch board from the hinge on the lid or it gets worn through from the hinge. Mine was worn through. The switches
purpose is only to connect the two board points to send the connection for power or shut down, hence your 2 wires touching together acts as the switch. I assume his issue was with the plug pulling out of the switch board when the lid opened as the wire didn't seem
to be shorting out. Or if it had rubbed through the insulation, not being connected to the switch board left it slack so it didn't short out on the hinge to the chassis. You can order the wire for 15-25 US or just make a new one with larger gauge wire as I did. I also left extra slack and added some extra insulation in the hinge area. I see it's a common problem, sorry it took me so long to get the issue in the shop. Hope this helps, even though its an old thread.