This is a forum for Nook Classic (two screens, small bottom screen color), Nook Simple Touch (one e-ink screen) and Simple Touch with Glowlight (Simple Touch with illuminated screen). Help us help you by indicating which model you are using.
If you are using either of the Simple Touch models please try the device after carefully cleaning all the way around the joint between the e-ink panel and the frame. A soft dry clean brush would be a good implement for the cleaning. Instead of a capacitive touch screen similar to those used in the other nook models, the two Simple Touch models use rows of infra-red lights and optical sensors hidden behind the frame. Dust, hair or lint along the edge of the screen can obstruct those sensors.
Please respond with the specific model of your reader and if's a Simple Touch if the cleaning helped. If you can operate it long enough it might also help to indicate the firmware version. Inquiries about other models might get more responses in other sections of the B&N forums/clubs