i press and hold button for 30 seconds...it will not reboot. How can I reboot my ipad?
Try doing a hard reset:
Press and hold both the Home button and the Sleep/wake button simultaneously for about 15 seconds and release when the Apple logo appears.
If that doesn't work, try : http://support.apple.com/kb/HT1808
Using that last article will erase everything on the device, so make sure you have a backup!
Retrieving data ...