CHAPTER 11 TROUBLESHOOTINGCOPYRIGHT © 1999 CANON INC. CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)11-584 The copy has uneven density. (darker at front)5 The copy has uneven density. (lighter at front)YES/NOYESYESNOCauseScannerTonercartridgeScanninglampTransferchargingrollerStep12ChecksClean the scanning lamp, reflectingplate, lens, and mirror. Is the problemcorrected?Turn off the power in the middle of acopying run, and open the machine. Isthe toner image on the photosensitivedrum before transfer more or lessuneven?ActionEnd.1. Replace the tonercartridge.2. Replace the scan-ning lamp.1. Mount the transfercharging rollercorrectly.2. Replace the transfercharging rollercorrectly.6 The copy is foggy. (entire face)YES/NONOYESNOYESCause------------ScannerGroundingspringScanninglamp, Devel-oping biasStep123ChecksIs the density correction dial (VR107)or the density adjusting lever set to themiddle setting?Clean the scanning lamp, reflectingplate, lens, and mirror. Is the problemcorrected?Set the drum unit in the machine. Isthere electrical continuity between thePCB of the base of the drum and themachine's top unit?ActionSet the dial or thelever to the middlesetting, and make acopy. If the image isstill foggy, to step 2).End.Check to see if thegrounding spring ismounted correctly (inreference to the drumdrive gear).1. Check the activationof the scanninglamp.2. Check the develop-ing assembly.
