My iPhone 16 Pro won't turn on!

Something is wrong with either your power, charger, cable, or port. That has caused the iPhone to not charge and is nearly discharged:

If your iPhone or iPod touch won't charge - Apple Support

thelaurawholived wrote:

Heya!

Thanks for replying. I have plugged him into my Mac Pro 1 & my iPhone, but he gives me the message that they can't recognize my battery and are not sure it is a genuine Apple part (which I'm sure it is, well hopefully since it's brand new).

When I unplug, he shuts off again.

From what I am hearing, you are getting an “Unknown Part” notification on your iPhone. Since you state you have never had your iPhone repaired, then your battery is likely not functioning as expected. You should make an appointment at your nearest Apple Store’s Genius Bar or Apple Authorized Service Provider for diagnostics and evaluation.

Learn more: About iPhone Parts and Service History - Apple Support

Make an appointment: Genius Bar Reservation and Apple Support Options - Apple

You have already tried a force reset, which I would have recommended. So now you should go back to wherever you purchase this new iPhone for a refund or exchange as it could possibly be defective.