Canon NP6512 Service Manual page 9

Making Pre-Checks
Clean the parts.
Scanning system,
pickup/feeding system,
delivery assembly
Is the copy density
NO
correction dial (VR107)
centered?
YES
Set it at
the center.
Select non-AE, and set the copy density
adjusting lever to the middle index; then,
make two to three copies of the Test
Sheet (NA-3).
Check the following:
1. Density of gray scale No. 9
2. Presence/absence of difference between front
and rear (Note 1)
3. Density of gray scale No. 1 (good or bad; Note 1)
4. Fogging of background (Note 1)
Adjusting the Optimum Density
YES
Is gray scale No. 9
barely visible?
NO
Can the
deviation be corrected
YES
using the copy density correction
dial (VR107)?
NO
Is the optimum
YES
density obtained by intensity
adjustment?
(Note 2)
NO
Check the following:
1. Drum unit
2. Scanning lamp
3. AE sensor PCB
4. DC controller PCB
5. Composite power supply PCB
(See the appropriate troubleshooting
procedure.)
D. Image Adjustment Basic Procedure
END
Note:
1. The machine is not equipped with a function to
correct image faults. See the appropriate
troubleshooting procedure.
2. See p. 2-38.
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