some of people suffer from problem when they have fully discharged the phone. With completely dead battery sometimes the device does not want to start charging.
First of all, you need a good quality wall charger. Plug the phone and wait at least couple of minutes hours to charge the phone.
To boot up the phone you need to use this simple trick:
Plug phone to charger and hold the power button for 18 or more seconds. After that the battery should start recharging.