I was wondering what the name of the 5th component was.
Dell 1747 Studio 17
Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up.
Sign up to join this communityAccording to pages 20 and 21 of the pdf located here, it's the battery status light.
Based on position, either a charging LED? What make/model of laptop do you have? It should be listed in the user's guide.