6.1.4. Uneven Image Density
Possible Cause (Scanner)
•
Dirty exposure glass
Action
•
Clean the exposure glass (for both book and ADF).
•
Replace the image sensor.
Possible Cause (Printer)
•
Poor drum sensitivity.
•
Dirty laser optic components.
•
The toner metering blade is deformed, or incorrectly positioned.
•
Uneven toner supply in the development toner hopper.
•
Quenching lamp defect.
Action:
1. Print a solid black test pattern, and open the cover in the middle of print-
ing.
2. Check if the toner is evenly distributed on the development roller.
•
If it is not, check the toner metering blade, and the toner supply mecha-
nism in the toner hopper. If yes, go to step 3.
•
If the image is lighter in the center of the image, toner may be low. Re-
place the CTM and supply more toner.
3. Check if the toner is evenly distributed on the drum.
•
If it is not, check the drum sensitivity, the laser optic components, and
the quenching lamp on the CTM.
•
If it is, check if there is any dirt on the transfer roller surface.
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TROUBLESHOOTING
May 22nd, 1995
COPY QUALITY TROUBLESHOOTING
6-6