I have tried holding the power button. I've tried holding both the power up and power down buttons while also holding the power button. I've tried holding both the power up and down button, while also holding the power and home buttons. None of these things are getting my phone to boot back up. What should I do?
Try holding the volume down and power buttons together for 20 to 30 seconds and see if that reboots the phone.
Have you tried charging the phone?