My iPhone 6 died last week. Took it to the Verizon store and they told me it was toast, but still under manufacturers warranty and gave me a number to call. I came home and called the number and the gal on the phone said to press the on/off button at the same time I press the round one on the front of the phone (don't know what it's called). She said to just hold them in for a little bit and it would reset my phone. Sure enough, it did the job, and my phone was back to working.