Q: iPhone 6 not switching on!

Try the steps in this article:

If your iPhone, iPad, or iPod touch won't turn on - Apple Support

Sorry to hear that. I will get resolved, hang in there... 

Sudden death no power iPhone 6 can be a failed tristar charging logic integrated circuit chip on the logic board, or a common short on the main power rail that can sometimes spontaneously occur.   Both of these are board level repair issues, however a local "screws and glues" independent repair shop can help you at least rule out simpler problems---like a bad battery or bad screen.   Independent repair is not sanctioned by Apple