3.3 DIRTY BACKGROUND
- Problem -
1. Dirty background at image density level 4 (manual setting).
2. Copies made in ADS mode have a dirty background.
- Possible Causes -
1. VL correction failure
• Very dirty optics (VL correction cannot compensate)
• Deteriorated exposure lamp (maximum output cannot give sufficient light
intensity)
• Failure of the dc power supply board
• Dirty erase lamp unit
2. VR correction failure
• CB (development bias) high voltage supply board failure
• Poor development bias terminal contact
• The development bias is grounded
3. The OPC drum is not grounded properly
4. ADS mode
• Improper ADS Density setting (SP5-106)
• ADS Sensor board failure
• CB high voltage supply board failure
• Incorrect adjustment of the ADS sensor (SP4-201)
• Sensitivity of the ADS sensor is not correct for the original
5. High toner density
• Improper setting of the drum charge voltage adjustment (SP2-001)
• Improper VSP pattern bias (SP2-203)
• Dirty erase lamp unit
6. Drum charge roller thermister error
• Connector of the drum charge roller thermistor id not connected properly.
• Broken drum charge roller thermistor
FSM 6-5 FT5535/4527/4522
To Next Page