title_body: Upgrade Kindle 4 system from 4.1.3 to 5.6
upvoted_answer: The firmware update page of Kindle does not list Kindle 4th generation notouch. Accoring to this answer and Amazon, your kindle is listed under 5th generation.
  
  The latest firmware version number for the Kindle 5th generation is 4.1.3 so you cannot update it to 5.6.0.