4. The copy has an uneven density (darker at front).5. The copy has an uneven density (lighter at front).COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 11 TROUBLESHOOTING11-72CausePrimarycharging wireDevelopingassemblyScannerPre-exposurelampDevelopingassemblyChargingassembly, CopypaperChecksPerform the Image AdjustmentBasic Procedure. Is the problemcorrected?Are the developing rolls of thedeveloping assembly firmly in con-tact with the photosensitive drum?Clean the scanning lamp,reflecting plate, side reflectingplate, mirror, lens, dust-proofingglass, and heat absorbing glass.Is the problem corrected?Is the pre-exposure lamp flashingduring copying?Is the developing cylinder coatedwith an even layer of toner?Step12345YES/NOYESNOYESNONOYESActionEnd.Check the developingassembly locking unit.End.1. Replace the pre-exposure lamp.2. Replace the DCcontroller PCB.1. Clean the tip of theblade of thedeveloping assembly(dry wiping).2. Clean the surface ofthe developingcylinder.3. Check the toner insidethe developingassembly to see if it islevel.1. Clean all chargingwires once again, andcheck their height.2. Try replacing copypaper.Download service manual and resetter printer at http://printer1.blogspot.com
