Why does my Nook HD's screen have frozen pixels or black lines?
My Nook HD screen is on and it's responsive but the screen has lines through it or dead pixels.
The 7 inch third generation of Nook color tablets by Barnes & Noble, not to be confused with the 9 inch Nook HD+.
Frank Poole, sounds like a bad LCD. Of course you always want to make sure that all the connections are properly seated. From your description, it sounds like you need a new LCD. This video will give you an idea of how to disassemble your Nook. A replacement LCD is available at places like this as well on here. Hope this helps, good luck.