PJL overview ....................................................................................................................77 Printer functions (all models)...................................................................................................78 Engine control system (engine control unit and power-supply assembly)........................78 Image-formation system....................................................................................................83 Print cartridge....................................................................................................................84 Printer paper-feed system.................................................................................................84 Jam detection in the printer ..............................................................................................85 HP LaserJet 3015 all-in-one unique components....................................................................87 Basic operation..................................................................................................................87 HP LaserJet 3020 and 3030 all-in-one unique components....................................................93 Scanner and ADF functions and operation ......................................................................93 Fax functions and operation (HP LaserJet 3015 and 3030 only) ...........................................96 PSTN operation ................................................................................................................96 The fax subsystem ...........................................................................................................96 Formatter in the fax subsystem ........................................................................................96 LIU in the fax subsystem ..................................................................................................96 Fax page storage in flash memory ...................................................................................99 5 Removal and replacement Removal and replacement strategy.......................................................................................103 Required tools..................................................................................................................103 Before performing service...............................................................................................103 After performing service..................................................................................................104 Parts removal order.........................................................................................................104 HP LaserJet 3015 all-in-one..................................................................................................107 Link assemblies and scanner support frame springs......................................................107 Scanner side covers........................................................................................................110 Separation-pad set..........................................................................................................111 Control-panel bezel.........................................................................................................112 Control-panel assembly...................................................................................................113 Media lever and media lever torsion spring....................................................................114 Separation pad assembly................................................................................................115 Scanner assembly...........................................................................................................118 Scanner assembly top cover...........................................................................................126 Top-cover assembly........................................................................................................129 Pickup roller ....................................................................................................................130 White platen.....................................................................................................................131 HP LaserJet 3020 and 3030 all-in-one..................................................................................133 ADF input tray..................................................................................................................133 Flatbed lid........................................................................................................................134 Link assemblies and scanner support frame springs......................................................136 Control-panel bezel.........................................................................................................139 Control-panel assembly...................................................................................................139 ADF separation pad ........................................................................................................140 ADF input-tray flag...........................................................................................................141 ADF pickup roller ............................................................................................................142 ADF scanner glass..........................................................................................................143 Scanner assembly...........................................................................................................145 Printer (product base)............................................................................................................153 Printer separation pad.....................................................................................................154 Print cartridge..................................................................................................................154 Printer pickup roller..........................................................................................................156 Media input tray...............................................................................................................158 Transfer roller..................................................................................................................159 Printer side covers...........................................................................................................161 ENWW v