Have you tried restarting or resetting the iPad?
Restart: Press On/Off button until the Slide to Power Off slider appears, select Slide to Power Off and, after It shuts down, press the On/Off button until the Apple logo appears.
Reset: Press the Home and On/Off buttons at the same time and hold them until the Apple logo appears (about 10 seconds).
No data will be lost.
If these do not work you could try restoring the iPad to Fatory condition to see if this solves the problem.
If nothing works the iPad likely has a hardware problem.