Canon imagePRESS C1 Service Manual - page 30
Contents
Chapter 14 Correcting Faulty Images
14.1 Making Initial Checks................................................................................................................................................14-1
14.1.1 Installation Environment.......................................................................................................................................................... 14-1
14.1.2 Checking of Paper.................................................................................................................................................................... 14-1
14.1.3 Checking of Paper Setting ....................................................................................................................................................... 14-1
14.1.4 Checking of the Durable Parts ................................................................................................................................................. 14-1
14.1.5 Checking of the Periodically Replaced Parts........................................................................................................................... 14-1
14.1.6 Checking of Each Unit/Checking Item of Each Function System........................................................................................... 14-1
14.1.7 Others....................................................................................................................................................................................... 14-2
14.2 Test Print ....................................................................................................................................................................14-2
14.2.1 Overview.................................................................................................................................................................................. 14-2
14.2.2 Test Print TYPE....................................................................................................................................................................... 14-2
14.2.3 Selecting the Test Print TYPE ................................................................................................................................................. 14-3
14.2.4 16-Gradation (TYPE=4) .......................................................................................................................................................... 14-3
14.2.5 Full Area Half Tone (TYPE=5) ............................................................................................................................................... 14-3
14.2.6 Grid (TYPE=6) ........................................................................................................................................................................ 14-4
14.2.7 MCYBk Horizontal Line (TYPE=10) ..................................................................................................................................... 14-4
14.2.8 64-Gradation (TYPE=12) ........................................................................................................................................................ 14-5
14.2.9 Full Color 16-gradation (TYPE=14)........................................................................................................................................ 14-5
14.3 Troubleshooting .........................................................................................................................................................14-6
14.3.1 Image Faults............................................................................................................................................................................. 14-6
14.3.1.1 Light Image / Weak Density .......................................................................................................................................................................14-6
14.3.1.1.1 When printing on CLC extra heavy paper (209g), light image occurs at solid black areas of output image .....................................14-6
14.3.1.1.2 Uneven density/light image: Developing high-voltage cable has poor contact ..................................................................................14-6
14.3.1.2 Uneven Density...........................................................................................................................................................................................14-7
14.3.1.2.1 When copying thin gray lines in Text/Printed Img. mode, moire-like image appears .......................................................................14-7
14.3.1.2.2 Uneven density (uneven gross) occurs when copying/printing high-density image with thick coated paper in use..........................14-7
14.3.1.2.3 Uneven density appears at 4mm intervals in main scanning direction ...............................................................................................14-7
14.3.1.3 Image Displacement/Out of Focus..............................................................................................................................................................14-8
14.3.1.3.1 Smeared image/hue variation (variation of drum potential) occurs in humidity environment ...........................................................14-8
14.3.1.3.2 Yellow displaced at trail edge of image upon installation: Screw on ITB connecting shaft is loosened ...........................................14-8
14.3.1.3.3 When duplex printing, position of image on both 1st and 2nd sides is displaced in sub scanning direction .....................................14-9
14.3.1.4 Partially Blank/Streaked..............................................................................................................................................................................14-9
14.3.1.4.1 Void occurs in main scanning direction on halftone area/oval-shaped patterns/E060-0000: J423 connector (11-pin CT connector) on
main body side of pre-conditioning unit has poor contact ..............................................................................................................................14-9
14.3.1.4.2 Void occurs in sub scanning direction upon installation: ATR shutter solenoid cable comes into contact with developing cylinder.14-
10
14.3.1.4.3 Measure against scratches made on Fixing Roller in circumferential direction: Lines appear in sub scanning direction ...............14-11
14.3.1.4.4 Lines (smeared image): Mylar comes off post duct in P-kit assembly .............................................................................................14-12
14.3.1.4.5 In low temperature environment, void occurs at border between halftone area and solid image area .............................................14-13
14.3.1.4.6 Fingerprint.........................................................................................................................................................................................14-13
14.3.1.5 Smudged/Streaked.....................................................................................................................................................................................14-14
14.3.1.5.1 Yellow vertical stripes on copy images/blank image on PG test chart printouts: PF-A board is faulty ...........................................14-14
14.3.1.5.2 Soiled back: Transfer roller B3 in Secondary transfer mount assembly is soiled.............................................................................14-14
14.3.1.5.3 Soiled back (patch mark) appears: HV8 PCB is faulty.....................................................................................................................14-14
14.3.1.5.4 Soiled back: A failure in cleaning the secondary transfer roller is caused .......................................................................................14-15
14.3.1.5.5 Dark spots appear on output image ...................................................................................................................................................14-15
14.3.1.5.6 The poor picture by the attachment mistake of seal support plate (front, rear) ................................................................................14-15
14.3.1.6 Ghost / Memory ........................................................................................................................................................................................14-17
14.3.1.6.1 Fixing Gloss Ghost............................................................................................................................................................................14-17
14.3.1.7 Faulty Color Reproduction........................................................................................................................................................................14-18
14.3.1.7.1 At scanner reading upon installation, faulty image occurs: S-B Board PCB has poor contact ........................................................14-18
14.3.1.7.2 Hue variation occurs: OFST value (target value) for PASCAL is changed......................................................................................14-19
14.3.1.7.3 Faulty gradation occurs with machine equipped with DADF-R1 after auto gradation adjustment (full adjustment) ......................14-19