If the Top (Sleep/Wake) button is inoperative, your iPad will require repair - as without this button it is impossible to trigger the necessary recovery process.
If your Top (Sleep/Wake) and Home buttons are operating correctly, you should be able to restart the iPad:
- On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

If iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad or iPod touch won't turn on or has frozen – Apple Support
If your iPad isn’t working correctly after you restart it, see the iPad Support website.