Paper-top sensor ............................................................................................................160 Fuser-wrap sensor ..........................................................................................................161 250-sheet feeder pickup roller ........................................................................................162 500-sheet feeder pickup roller ........................................................................................163 6 Troubleshooting Chapter contents....................................................................................................................167 Basic troubleshooting ............................................................................................................169 Clearing jams ........................................................................................................................171 Where to look for jams ....................................................................................................171 To clear jams from inside the printer ..............................................................................171 To clear jams from input areas .......................................................................................172 To clear jams from output areas .....................................................................................174 Control panel light messages ................................................................................................176 Supplies Status lights .....................................................................................................177 Printer Status lights ........................................................................................................182 Solving image-quality problems ............................................................................................190 Print-quality checklist ......................................................................................................190 Solving image-quality problems (all print jobs) ...............................................................190 Solving image-quality problems (color print jobs) ..........................................................200 Resolving problems that generated messages .....................................................................204 Messages for both Windows and Macintosh ..................................................................204 Messages for Windows only ...........................................................................................204 Resolving problems that did not generate messages ...........................................................206 Troubleshooting checklist ...............................................................................................206 Checking the network .....................................................................................................207 Solving general printing problems ..................................................................................207 Solving PostScript (PS) errors ........................................................................................212 Solving common Macintosh problems ............................................................................213 Manually rotating the print-cartridge carousel ................................................................216 Functional checks .................................................................................................................218 Engine test ......................................................................................................................218 High-voltage power-supply check ..................................................................................219 Paper-path check ...........................................................................................................219 Service mode functions .........................................................................................................221 Cold reset .......................................................................................................................221 NVRAM initializer ............................................................................................................221 Error report......................................................................................................................222 Super NVRAM initialization.............................................................................................222 Network card cold reset...................................................................................................222 Using PJL commands .....................................................................................................223 Troubleshooting tools ............................................................................................................225 Demo page .....................................................................................................................225 Configuration page .........................................................................................................225 Supplies Status page ......................................................................................................226 Repetitive image defects ................................................................................................227 General timing charts .....................................................................................................228 Locations of connectors ..................................................................................................230 Dc controller connections ...............................................................................................233 Main wiring diagram .......................................................................................................234 HP LaserJet Toolbox .............................................................................................................236 To view the HP LaserJet Toolbox ..................................................................................236 7 Parts and diagrams Chapter contents ...................................................................................................................237 vi ENWW