COPYRIGHT © 1998 CANON INC. CANON NP7161/NP7160 REV.0 AUG. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 10 TROUBLESHOOTING10–3918. The copy has a blurred image.Scanner cableScanner railPhotosensitive drumDeveloping gearDrum drive system1234Does the cable wind on the cablepulley in layers while the scanner ismoving?Move the No. 1 mirror mount slowlyby hand. Does it move smoothly?Is the problem noted at intervals ofabout 9.4 cm?Is the problem noted at intervals ofabout 3.2 cm?1. Route the cable once again.2. If the cable is twisted or frayed,replace it.Clean the surface of the scanner railwith alcohol. Then, apply a smallamount of lubricant.1. Check the drum gear.2. Check the end of the drum (incontact with the developing roller)for scratches and protrusions.Check the developing assembly.Check the drum drive system.ActionsCause Yes/NoChecksYESNOYESYESNOStep19. The copy is foggy. (horizontally)Scanning lamp(LA1), Lampregulator PCBDeveloping rollerDeveloping biasScannerFeeding assemblyIs the problem noted at the samelocation on all copies made in Direct?Does the scanning lamp flicker whenthe scanner is moving forward?Is the developing roller soiled withtoner, is the roller deformed, or is thearea in contact with the developingroller (photosensitive drum) soiledwith toner?Is the developing bias appliedcorrectly?Make a copy in Reduce, and compareit with a copy made in Direct. Is theproblem noted in a different location?ActionsCause Yes/NoChecksGo to step 4.Check the scanning lamp and thelamp regulator PCB.Clean or, if necessary, replace thedeveloping roller.Remove the developing assembly,and check the wiring; then, set it onceagain.Check the scanning system.Check the feeding assembly.YESYESYESNOYESNOStep12345
