Couple of things I see over there:
1) On the PMS, the button GND cable seems to be shorting CHRG to ground.
2) The pms itself looks a bit like a mess, there's cold soldering everywhere and missing pads where the BTN pad should be.
3) some people reported instability booting with one cell so try 2.
4) on the wii there's also cold soldering everywhere, I strongly suggest you practice your soldering skills on a scrap board. What soldering iron do you have? can you adjust the temperature on it? if you can, you might need to crank it up a bit. If you can't you should get one that has that feature.
5) check that U10 works... It should be sending 3.3v when you turn it on.
6) you mention the *voltages* are fine but what about the resistances to ground and to themselves? can you post your actual measurements? did you find the thread I was talking about?