I have seen other threads addressing this problem but none seemed to fit my exact problem. The phone was occasionally turning off by itself and eventually it would not turn back on. I plugged it into the USB charger and a wall charger, but neither indicated any charging. I left it plugged in all night but still nothing. The phone won't even come up to the Samsung logo by holding the power key, I need to take out the battery and put it back in, then it will come to the logo and turn off again. I cannot to a hard reset. When i go through the process the phone turns off while i am at the "are you sure you want to format?" question. Any suggestions? Thanks!