7.1.11. Faint Copies
Possible Causes (Scanner)
•
Scanner shading correction error or wrong scan threshold.
•
Contact image sensor (LED, sensor element) defect
Action:
•
Do the image sensor initialization by service function 10 (Shading Test).
(Refer to section 4-1.)
•
Adjust the scan threshold settings.
•
Replace the image sensor.
Possible Causes (Printer)
•
Poor drum sensitivity.
•
Dirty laser optic components.
•
Incorrect development/ transfer bias.
•
Low toner.
•
Low fusing temperature.
Action:
1. Check whether the toner saving feature has not been selected with the
user parameters. (If it has been selected, there is no problem.)
2. Print a test pattern, and open the cover in the middle of printing.
3. Check if the toner on the paper at the entrance of the fusing unit looks
faint or not.
•
If it does, check or replace the fusing lamp, thermistor, and PSU.
•
If it does not, go to step 4.
4. Check if the toner on the drum looks faint or not.
•
If it does, go to step 5.
•
If it does not, check the connection between the transfer bias terminals
and high voltage power supply.
5. Check if the toner on the development roller looks faint or not.
•
If it does, check all the connections between the development roller and
the high voltage power supply.
•
If it does not, try replacing the DTM.
TROUBLESHOOTING
July 30th, 1996
COPY QUALITY TROUBLESHOOTING
7-10
