try googling repair a frozen kindle screen, or hold slider button for about 30 seconds and then while holding slider in on position push on home key for about about 20 seconds and a screen should come up where you can type in reset and it will change screen to recovery mode and then push r button and your kindle will start again, you do lose books but they are easy to replace back on kindle if you have them in a library on pc. This is better than a kindle that doesnt work, please note this is for the kindle keyboard ereader.
Hope this helps at least one person!!!!
Regards Viv