For anyone who went to the troubleshooting area and read about just plugging your phone in for half an hour to try to turn on your phone, but knew or learned that the battery was not the issue! I have learned of a trick to turn it on without having to press the reset button!
Press and hold the power button AND the volume up/down buttons at the same time until your phone vibrates and the LED starts blinking red. The SONY screen will show up. Wait for a few seconds. It will then go to the charging screen. After that, power on your phone (holding down the power button) and it should power on as nomal. Make sure you can go through your phone like your normally would (I suggest checking settings, albums, an app, and messaging/email) and it should be fine.
I was told by my service provider that it could have turned off because too many apps were running at once and it stalled out. So throughout the day, make sure to regularly close all apps fully. It could have also turned off just because electronics like to do that here and there.
