It's happened about 6 times. 4 of them were today. The last time I hit the Google icon to go to the net. Phone goes black scren, I have figured out how to get it back. I have to pull the sim, plug it in to a charger. When the battery icon shows I can power it up, then slide the sim in. That's a general description, sometimes it's in a endless boot mode. Wounded if its a power problem,because the turbo charger stopped working 3 days ago. I use my wife's Samsung USB charger to charge my phone now. Any ideas? What could the issue be?