Maintenance units The user replaces the following maintenance units as part of periodic maintenance. Chapter 4 explains the maintenance procedures. Color toner cartridges Transfer charger Black toner cartridge Cleaning roller Imaging drum Charcoal filter Air filters Fuser Transfer drum Paper rollers Transfer belt The printer keeps track of use on some of its user-replaceable parts. Because maintenance unit life is tracked by the formatter board by page count, swapping maintenance units between printers might cause a misrepresentation of maintenance unit life values. 224 Chapter 6 - Removal and replacement EN