Presumably, if you are staying here, your favorite gadget that is iPad / iPad 2 / ipad 3 or even the newest iPad mini / iPad 4 got completely frozen, it decided not to turn on or does not respond to your Home button push in its turn-on state. Your are completely sure that iPad's battery is full but gadget seems to be dead. Don't panic, the solution can come quickly and easily:
If your iconic tablet got frozen due to the failure of some application but his display in the turn-on state press and hold the Sleep/Wake button for a few seconds until a red-slider-image appears on the screen, then press and hold the Home button until the problematic application quits.
If that doesn’t work, turn itablet off, and then turn it on again. To do this press and hold the Sleep/Wake button until a red slider appears, then drag the slider. Then press and hold the Sleep/Wake button until the Apple logo appears.
If that doesn’t work, reboot iPad that is press and hold both the Sleep/Wake button and the Home button for at least 10-20 seconds, until the Apple logo appears. Mind you, keep holding both buttons even after the red power off slider appears (sometimes, the time to hold both buttons may be as much as 60 seconds.)
The last procedure is the only way to unfreeze iPad / iPad 2 / iPad 3 / iPad mini / iPad 4 when it is in its turn-off state but does not want to be turned on by the Sleep/Wake button. In most cases the reboot will trigger the Apple logo and once it appears,release the buttons and let the ipad load. But if it does not do this and is stuck (after reboot) either on Apple logo or spinning little circle connect iPad to computer, wait up to 30 seconds and launch up iTunes ( it should be already installed and be updated) and wait for a while. It may fix your problem, iPad will appear in iTunes and operate normally.
If all above steps failed and your gadget continues to be frozen or repeatedly restarts but never stops on the Home screen or shows only the logo of Apple with no progress bar further, or is no longer recognized in iTunes put iPad into recovery mode