Tried this? Two Button Reset: press and hold the Volume Up button at the same time you press the Power button. Continue holding the buttons for 15 seconds or until the screen goes completely black and there is no haptic feedback from the Windows button beside the screen. Once the screen is black, wait for about 10 seconds and power the Surface back up.
Sent from my Lumia 1020
Try opening it up and removing and reinserting the battery
BothYou obviously have no idea about the SP3......or are a dab hand with the heat gun!!