Abstract: In a document handling system for moving documents for imaging over a transparent platen that is subject to contamination, and having a shared repositionable document illumination system that is normally positioned in a park position substantially spaced from this moving documents imaging platen area, wherein in response to lifting the document handling system and the activation of a diagnostics routine, which can be activated from detected image contamination, the repositionable document illumination system is automatically moved under the moving documents platen and activated to illuminate that platen area from underneath to illuminate the contamination thereon for cleaning.