No power up (by 3 users)

So I picked up a multimeter and disassembled the laptop last night.
1st, I confirmed that the power cable is live, which it is.
2nd, I confirmed that the power jack is live (when the cable is plugged in, the internal contacts are live), which it is.
3rd, I confirmed that the contacts to the motherboard are live (when the cable is plugged in, the soldered contacts on the opposite side of the board are live), which they are.
So, I can confirm that power is getting into the motherboard without any problems. And the jack is still very secure on the board (since I know a lose jack is a common problem). Unfortunately, once the power disappears into the board, I've no way to trace where it's going. And no matter how hard I look and how many helpful sites I find, none of them have a repair manual or schematics manual for this model of computer. I couldn't even find one to tell me how to get it apart, had to rely on eyesight and intuition to figure out that part. ;-)
So, can anybody give me any hints where else I can look for the problem? Visual inspection reveals no clearly fried circuits, but that doesn't mean they don't exist. And the battery contact is like 7 pins, and I can't tell where on there is supposed to be + or -, so I don't want to start sticking my multimeter anywhere that I don't know what the flow is. ;-)
Any hints would be appreciated, thanks!

I've had the exact same issue. Confirmed power is getting to the jack, but no battery lights, no 'plugged in' indicator, and it doesn't turn on. Definitely not a power-lock problem, since the lights would still be on in that case, at least.