How to Restart an iPad that won't turn on
1. Recharge - and keep recharging
The most common cause of ‘the black screen of dread’ is the fact that the iPad battery is so drained that nothing, not even the red empty battery icon, can be displayed. The iPad has a much bigger battery than the iPhone so leave it charging for at least an hour from a proper power adaptor rather than a USB lead from a computer.
To reset and restart your iPad hold down the Sleep/Wake button on the top right of the tablet while simultaneously pressing down the home button. Keep both buttons depressed until the iPad restarts – this can take up to 15 seconds, so persevere.
If the red slider appears or the screen dims, keep pressing until the Apple logo appears.
3. Recovery mode
If the previous solutions have not worked then you can try to force your iPad into recovery mode and then Restoring it to factory settings. Please be aware that doing this will erase all data on your iPad – which you should be able to recover from a recent backup.
We recommend to try them one at a time, in the order they appear in the article. And hopefully the end result will be a fully working iPad in your hands.