This article list out the guide for basic troubleshooting iPad by reset, recovery and restore iPad if crash due to iOS update.
(A) Try reset iPad
Hold down the Sleep/Wake button and the Home button at the same time for at least ten seconds, until the Apple logo appears
(B) Try reset all settings
Settings > General > Reset > Reset All Settings
(C) Setup as new (data will be lost)
Settings > General > Reset > Erase all content and settings
FORCE IPAD INTO RECOVERY MODE
1. Turn off iPad
2. Turn on computer and launch iTunes (make sure you have the latest version of iTune)
3. Plug USB cable into computer’s USB port
4. Hold Home button down and plug the other end of cable into docking port.
DO NOT RELEASE BUTTON until you see picture of iTunes and plug
5. Release Home button.
6. iTunes has detected iPad in recovery mode. You must restore this iPad before it can be used with iTunes.
7. Select “Restore iPad”…
1. Data will be lost if you do not have backup
2. You must follow step 1 to step 4 VERY CLOSELY.
3. Repeat the process if necessary.