iPhone 12 blacked out

Hey there,

Do you mean your iPhone won’t turn on or it’s on but the screen is black?

And how did this problem happen to you?

During answer this question try force restart your iPhone to see if it will solve this issue:

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.

Hello ~ Take a look at this helpful link by clicking below…

If your iPhone won't turn on or is frozen - Apple Support

Inside the link you may click on the applicable link and try those links. I hope this helps.

~Katana-San~