Hello, I'm Denise Garcia. My iPhone 8 went off while watching a tube video and will not power back on
What is wrong with my IPhone 8+?
iPhone 8 Plus, iOS 14
Question marked as
You can try some basic steps like charging the device for atleast 15 minutes or force restarting it.
If it still won't turn on, you may follow https://support.apple.com/HT201412.