I had EXACTLY the same issue. I woke up in the morning and the bottom half doesn't work. Many sites say this is because i have dropped it or the screen was impacted but I know this is not the case. I then found screens for £15 on e-bay and thought this was fairly cheap and tutorial videos on how to fit them so was prepared to do this myself. My dad works with someone who knows a lot about this stuff so I got him to check it out and he said that replacing the screen would be a nightmare as they glue the screens on newer versions such as mine. He said it would be easier and cheaper to buy a second hand one for around £30. I'm not happy with this as I think its such a shame to throw it out and I don't want to go through the pain of transferring books etc as I can't remember my amazon login. So I guess the answer is to find a cheap second hand one or go without as all the other methods don't work.