are you positive that you turn the on/off knob to the right side? often people who messed with it, return it in backwards so that its the other way around.
The switch must be in the on position for it to charge!!!
Also make sure you pushed the plug in allright, all the connections are good and that the little led on the adapter is on, this means its receiving power and the prob is elsewhere.
Open grips make sure evrything is in the right place and check the board for any abnormalities.
If that fails maybe your battery is dead or the board is fried (highly unlikely if u used WDP charger), you'll have to get a new one
good luck