Ok so one thing that needs to be cleared up on this one the PMU reset he attempted to do is the proper way to do it on the unibody MacBook/MacBook Pro model computers. As this one has the removable battery to reset the PMU he would need to remove the power cord and the battery then hold the power button for 5 seconds.
As for the issue he is getting I do suspect the logic board based on the fact that the smu chip is integrated into it and we are getting no power through either an adapter connection or a battery connection.
If you can test the adapter on another mac to make sure it is working properly so that you can rule out that being an issue at all.
Best Regards,
Xen