I'm sorry about the issue. Was it working fine previously? When did this issue first occur?
Have you tried to press and hold the Power on/off button on the Nook device for about 45 seconds, then turn it back on and check?
If that does not work, can you please check at the back of the nook for any model? And are you able to go to settings on the nook and reset it to factory defaults?
Please reply at the box below to continue troubleshooting. Thank you.