11-3COPYRIGHT © 1999 CANON INC. CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)I. MAINTENANCE AND INSPECTIONA. Image Adjustment Basic ProcedureMaking Pre-Checks Adjusting the Optimum DensityClean the parts.Is the copy densitycorrection dial (VR107)centered?Set it atthe center.Select non-AE, and set the copy densityadjusting lever to the middle index; then,make two to three copies of the TestSheet (NA-3).Check the following:1. Density of gray scale No. 92. Presence/absence of difference between frontand rear (Note 1)3. Density of gray scale No. 1 (good or bad; Note 1)4. Fogging of background (Note 1)NOYESScanning system,pickup/feeding system,delivery assemblyCheck the following:1. Drum unit2. Scanning lamp3. AE sensor PCB4. DC controller PCB5. Composite power supply PCB(See the appropriate troubleshootingprocedure.)Is the optimumdensity obtained by intensityadjustment?(Note 2)Can thedeviation be correctedusing the copy density correctiondial (VR107)?Is gray scale No. 9barely visible?ENDYESYESYESNONONONote:1. The machine is not equipped with a function tocorrect image faults. See the appropriatetroubleshooting procedure.2. See p. 11-42.
