Have you tried a reset to see if it then restarts properly ? Press and hold both the sleep and home buttons for about 10 to 15 seconds (ignore the red slider if it appears), after which the Apple logo should appear - you won't lose any content, it's the iPad equivalent of a reboot.
Otherwise at the bottom of this page it says that if you just have an Apple symbol on the screen to :
- Connect iPad to your computer and open iTunes.
- If the iPad appears in iTunes, select the iPad and click Restore on the Summary pane.
- If the iPad doesn't appear in iTunes, try using the steps in this article to force iPad into recovery mode.