What do I do if my iPhone won't turn on at all?

If none of the above methods work and your iPhone won't turn on or charge. I think it would be necessary for you to force Restart the iPhone again. If the iPhone has power but the software has crashed, the screen may remain black even though the device is technically on. A force restart is designed to interrupt that crash cycle without needing to use the touchscreen.

The button sequence varies by model:

For iPhone 8, X, 11, 12, 13, 14, 15, 16, and newer (including SE 2nd/3rd gen): Quickly press and release the Volume Up button, then quickly press and release the Volume Down button. Finally, press and hold the Side button (power button) and keep holding it until the Apple logo appears. This can take longer than 10 seconds, so do not release the button if the screen remains black initially.

For iPhone 7 and 7 Plus: Press and hold both the Side button and the Volume Down button simultaneously until the Apple logo appears.

For iPhone 6s and earlier (including SE 1st gen): Press and hold both the Home button and the Top (or Side) button at the same time until the Apple logo appears.

If you fix the iPhone won't turn on or charge error, your iPhone will restart as if it were new. You can then set it up and restore your data from a backup. If the iPhone fails to restore and remains stuck, it may indicate a hardware issue that requires professional service.