Apple is coming to the rescue if your iPhone 6s or 6s Plus won't turn on. And by rescue, I mean it's helping solve a problem it created.
The company has determined that a powering on issue with the 6s and 6s Plus might be due to one specific component, and it's offering a new service program for repairs.
The issue affects devices within a limited serial number range that were manufactured between October 2018 to August 2019.
Visit the Apple Support page and enter your serial number to find out if your phone is eligible for the free repair. If it's eligible, you'll need to find an Apple authorized service provider, make an appointment at an Apple store, or contact Apple Support to arrange mail-in service via the Apple Repair Center.
Before you do anything, Apple strongly suggests making sure your phone is backed up. But if you can't get your phone to turn on, then a backup might not be in the cards.