Phone will not power on

Try hard resetting the phone. Holding the home button (button at the bottom of the screen) and the sleep/wake button at the same time for about 8 seconds. If this does not work, it generally means there is a hardware issue and you'll need to get it repaired or replaced. You can contact Apple Support or go into your nearest Apple Retail Store.

Connect iPhone to the Wall Charger for 10 minutes, the iPhone may turn ON itself. If still OFF, keep on the Wall Charger and Reset, hold both the home and power buttons for about 20 seconds until the iPhone begins to start.