Lumia 1020 :: Phone Won't Turn On (not Able To Soft / Hard Reset - NSRT Does Not Detect The Phone )

Yesterday, I went running with my Lumia 1020 listening to music and using the Runtastic app. The music stopped - I looked at the phone - it was turned off. I tried powering on, but to no avail. I should also mention that upon leaving, the battery was fully charged and this happened after some 20 minutes. When I came home, I immediately put the phone on the wall charger and expected it to power on after a while. I checked it after 3 hours and nothing, the phone was still stone-dead and what was even more worrying, completely cold - no heat-up from charging.

I tried connecting it to my PC - the computer didn't even recognize ANY device was connected to it. Just to be sure, I tried Nokia Software Recovery Tool, but sure enough, it was not able to detect the phone. The phone seems to be dead meat now, but when I put it on my desk wireless charging stand, the stand's indicator lights up, although the phone does nothing and stays that way.