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Confidential
4.2 Troubleshooting According to Image Defect
End users can solve problems related to image defects as long as they follow the User 
Check items. If the problem still cannot be solved, implement each procedure according to 
the step numbers in the tables below.
4.2.1 Light
 Electrodes location of the toner cartridge and drum unit
Fig. 1-6
 Electrodes location of the machine
Fig. 1-7
<User Check>
- Check the usage environment of the machine. Using the machine in 
hot-humid or cold-dry conditions can cause this problem.
- If the whole page is light, toner save mode may be ON. Turn OFF 
the toner save mode.
- Adjust the density using the Density Adjustment.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step Cause Remedy
1
Dirt on electrodes of the drum unit 
and those of the machine
Clean the electrodes of the drum unit and 
those of the machine. (Refer to Fig. 1-6 or 
Fig. 1-7.)
2
Toner type determination failure 
when a new toner cartridge is 
detected
Reset the toner manually. (Refer to “6. 
RESETTING TONER MANUALLY” in 
Chapter 4.)
3 Fuser unit failure Replace the fuser unit.
4
High voltage power supply PCB 
failure
Replace the high voltage power supply PCB 
ASSY.
5 Laser unit failure Replace the laser unit.
6 Main PCB failure Replace the main PCB ASSY.