5-24 Phaser 8400 Color PrinterAnalyzing Service Test PrintsA variety of test prints are available in the Hidden Service Menu to aid in determiningthe quality of output from the printer and to assist in troubleshooting problems. Thissection shows how to select and analyze all test prints available to the Phaser 8400printer. To access the Service Tools menu: From anywhere within the menu (notdiagnostics), press and hold the Up Arrow button, then press the OK button. You canalso press and hold the Cancel button, then press the OK button. To enter the HiddenService Menu: from the Service Tools menu, press and hold the Up Arrow and DownArrow buttons.NoteDefects revealed by the prints may not occur in the course of ordinary printing. Inservicing the printer, you should minimize the defects shown by the prints but notnecessarily eliminate them.Test Print Examples1: Weak/Missing JetThis print shows which jets are not outputtingenough, if any, ink compared to its neighboringjets. Note that the yellow jets’ bands have asmall amount of cyan ink added to them, whichtints them green, to make them more visible.Look for: No interlacing is used in this print;expect light/dark variation between jets. Lookfor much lighter colored vertical bands in thehorizontal bars. Weak jets in the yellow bandare distinguished by a cyan tint.Causes: A jet may be partially clogged;perform printhead clean/purge cycles on theprinthead to remove contaminants from thepoorly-performing jet. If jet substitution mode isrequired, see "Jet Substitution Mode" onpage 6-9. Test the purge system and the wiperblade performance. Turn the printer off for 4 to 6hours (or overnight, if practical). Then perform aclean/purge cycle again. There may be aproblem in the purge pump assembly or thewiper assembly may not be compliant. Verifythat Xerox ink is being used. Follow theinstructions on the “Printhead TroubleshootingChecklist”.74 75 76 77 78 79 80Weak jets8400-138
