Force restart iPhone 12 when not working or a frozen screen
If your iPhone isn’t responding, frozen, or doesn’t power on, and you unable to touch or you can’t turn it off or on so in this case you can try forcing it to restart. Restarting your Apple iPhone 12 / iPhone 12 Pro / iPhone 12 Pro Max can help if you experience continuous resetting / rebooting, crashing, freezing or if the touchscreen is unresponsive.
Note The steps to force restart the iPhone depending on the model. To learn what model you have, see the Apple Support article Identify your iPhone model.
Force restart iPhone 12 Steps:
Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the side button. When the Apple logo appears, release the button.
If iPhone doesn’t restart after you try these steps, see the Apple Support article If your iPhone won’t turn on or is frozen. Or if your iPhone isn’t working correctly after you restart it, see the iPhone Support website.