HP 8550 Service Manual - Page 478

Image faults The table below lists common image faults and the location of the information that can be used to solve them. Many of the symptoms will be addressed by troubleshooting the print engine. Always determine if the image fault appears on printed pages (indicating a need to troubleshoot the printer) before troubleshooting the copy module or ADF. Table 90. Common image faults Symptom Description Page Light The output image is too light 477 Dark The output image is too dark 479 Blank The copier fails to generate images 479 Solid black/solid color The copier generates a solid-black copy or an 480 image in solid color Soiled image/soiled back The face or back of copy paper is soiled 481 Vertical band/vertical line (sub scanning The copy has vertical lines (sub-scanning 483 direction) direction) White bands/white lines (vertical; sub scanning direction) The copy has white vertical lines (sub-scanning 484 direction) Horizontal bands/horizontal lines (main The copy has vertical lines (main scanning 485 scanning direction) direction) White bands/white lines (horizontal; main The copy has white vertical lines (main scanning 486 scanning direction) direction) Absence of specific color The copy has a specific missing color 486 White spot The copy has white spots 487 Fusing fault The copy has an inadequately fused toner image 488 Distorted image/displaced color The copy has a distorted or color-displaced 488 image Uneven image The copy has smudged or uneven image 489 Dots The copy has an image covered with dots 490 Ghost The copy has a (positive) ghost image 490 Soiling (double-sided copy) The face or back of the copy paper is soiled 491 (when made in double-sided copying mode) Copy module faulty image troubleshooting The problem is not noted on a test print, and is 491 obviously a problem with the copy module 476 Chapter 7 - Troubleshooting EN