Press and hold the side button or Sleep/Wake button (depending on your model) until the Apple logo appears. If iPhone doesn’t turn on, you might need to charge the battery. For more help, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen.

How do I turn iOS back on?

To downgrade iOS, you’ll need to put your iPhone into Recovery Mode. First power off the device, then connect it to your Mac or PC. The next step after thatdepends on what device you’re looking to downgrade.

Why wont my iOS turn on?

If your iPhone won’t turn on, most of the time a simple restart will get it back up and running. If you can’t restart your iPhone, then make sure it’s charged. You might need to replace the Lightning cable and make sure the power source is working properly.