6s iphone-dark screen and suggested start up method didnt work

What was the "suggested start up method" that did not work?

If it was a Forced Restart......Force restart iPhone - Apple SupportApple SupportOfficial Apple Support › guide › iphone › ios.......then there is a hardware problem with the phone.

At this point, due to the age of the iPhone 6s......I doubt that Apple will offer repairs, but you could give it a try and make an appointment at the Apple Store / Genius Bar or take the phone to an authorized Apple service shop.

You can find a list of authorized shops in your area using this link:

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