HP Color LaserJet Managed MFP E77428
Troubleshooting. Image Defects 2
Horizontal periodic light/dark band or dot
Step | Cause | Action |
---|---|---|
1 | Horizontal periodic band (CR, 94.2 mm) - OPC was left exposed for too long. - OPC is damaged by a high voltage in a short amount of time. |
This problem will resolve itself over time. If the problem is not resolved, replace the drum unit. |
2 | Horizontal periodic light/dark band (Magnetic roller, 31.4 mm). - The Magnetic Roller is in poor condition. - V-groove of the Magnetic Roller surface is not uniform. |
Replace the developer unit. |
Foggy image
Step | Cause | Action |
---|---|---|
1 | Voltage of OPC is abnormally low. | Replace the Drum unit. |
2 | HVPS operates abnormally. - HVPS is damaged or broken |
Replace the HVPS board. |
3 | Toner is over supplied. TC sensor operates abnormally. |
Replace the toner cartridge. |
4 | Voltage of OPC is abnormally low. - T1 voltage is abnormally high. |
Check the T1 connection in the HVPS. Check if the T1 roller spring in the ITB is connected correctly. Replace the HVPS board. |
Light image
Step | Cause | Action |
---|---|---|
1 | Typical faulty images (TRC) operates abnormally. | Perform TRC three to four times. |
2 | Poor transfer has occurred. | Force a jam during the print job. Check the image on the image transfer belt (ITB). If the image on the ITB is normal, refer to the “Blurred image” section. |
3 | Toner is empty. Toner is abnormally supplied. | Check if the toner level is sufficient. If not, replace the toner cartridge. Check if the toner supply shutter is opened. |
4 | Output voltage of the HVPS is abnormally low. - Color density decreases. |
Replace the HVPS board. |
5 | TC down and toner spills. | Replace the developer unit. |
6 | Toner spills by eraser. | Check if the eraser is contaminated. Replace the drum unit or developer unit. |