My phone drained to zero last night. When I plugged it in I noticed not even the charge indicator led came on. I verified that my charger was working by checking it with another device. I left the phone plugged in over night and this morning tried the volume Up/Down power and home button method along with the just volume down and power method. Nothing worked and my phone is still black and unresponsive.
Currently leaving phone plugged into different 2.1A charger. Tried plugging it into a pc to see if I got a different response. Don't know what to do from here.
NOTE: Yes, I know some phone batteries are not so easy to get to, on some devices. In such a case, make sure that your phone is not under warranty still before you try opening it up yourself. If it is under warranty, then contact the manufacturer first.
Try the following and see if it will turn on.
Remove the battery.
Press and hold the "Power" button for 20 seconds.
Now put the battery back in.
Plug it in to charge and allow it to fully charge before turning it on.
If this doesn't help, and you already tested the charger cord, then check the battery to see if it needs replacing.
If you still can't get it working, and if it isn't under warranty, then I would try a local tech.