HP Color LaserJet MFP E78330
Troubleshooting. Image Defects 1
Vertical black band
Step | Cause | Action |
---|---|---|
1 | Charge roller (CR) is contaminated. | Check if the CR is contaminated. Replace the drum unit if there are additional problems. |
2 | ITB belt is contaminated. • ITB cleaning is poor. • ITB cleaning blade is partially broken. |
Check if the ITB belt is contaminated. Replace the ITB cleaner if there are additional problems. |
3 | The scanner unit is contaminated. • Scan glass contamination • Mirror contamination • CCD sensor contamination |
Wipe the contaminated part of the surface with a soft cloth. CAUTION:The scanner unit contains fragile parts. Use caution while cleaning. |
Vertical white band, light band
Step | Cause | Action |
---|---|---|
1 | A foreign substance is between the magnetic roller and the blade. No toner on magnetic roller. |
Remove the foreign substance. Make the hook (transparency sheet is recommended.) Put the hook into the gap between magnetic roller and blade. Pull out foreign substances. |
2 | The developer in the developer unit is empty or the developer unit life has expired. | Check the life remaining of the developer unit on the supply information report. – If its life has expired, replace the developer unit. Check if the developer layer on magnetic roller is uniform. – If the developer layer is short, replace the developer unit. |
3 | The laser beam path is blocked. (Foreign substance is on the laser scanner assembly window.) |
Clean the laser scanner assembly window. |
4 | The OPC is scratched or contaminated in a vertical direction. | Replace the drum unit. |
5 | ITB cleaner or T2 transfer unit is contaminated with paper dust build up. - ITB cleaner contamination |
- Clean the paper dust stick on a regular basis. NOTE:The paper dust stick (Callout 1 ) may vary depending on the product. NOTE:Clean the paper dust stick on a regular basis in order to prevent horizontal light band. Frequent cleaning can help maintain product quality. HP recommends to clean this item when replacing TCU at a minimum. - T2 contamination (Callout 1) & Image defect |
Horizontal periodic black band or dot
Step | Cause | Action |
---|---|---|
1 | Horizontal periodic band or dot (CR 37.7 mm). - The surface of the Charge Roller (CR) is contaminated. - CR is scratched. |
Clean the contaminated surface on the charge roller with a soft cloth and alcohol. If the surface is scratched, replace the drum unit. |
2 | Horizontal periodic band (CR, 37.7 mm). CR in poor condition. |
Replace the drum unit. |
3 | OPC is damaged. | Replace the drum unit. |