My sisters G4 would not charge properly, at first it looked like a bad connection to the power however the root problem was the inboard DC. .
Following the instructions I was able to do the repair in under 20 minutes and the G4 is now up and running. Easy enough and she should have let me do this two years ago when it first acted up
I've nothing really to add to the instructions, my model was no 100% the same but everything worked out, just keep track of your screws and there are no issues.