Iphone x power off with broken screen

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If your screen is black or frozen

If your screen is black or frozen, you might need to force restart your device. A force restart won't erase the content on your device. You can force restart your device even if the screen is black or the buttons aren't responding. Follow these steps:

• On an iPhone 8 or later: Press and quickly release the Volume Up button. Press and quickly release the Volume Down button. Then press and hold the Side button until you see the Apple logo.

Take it to Apple for screen repairs. If you go through the force restart and release the side button when the screen goes black, and before the Apple logo appears, it will be off too.

If the screen remains unresponsive, then you cannot shut it off. The only two ways to power it off are via the settings app (requires screen input) or holding the power button and swiping to slide off. If you cannot enter anything at the screen you cannot power it off. Take it in to Apple or an Authorized service center to get the display replaced.