HP LaserJet M177 Color Pro MFP
Troubleshooting. Repetitive image defects ruler
If the product output has a consistent, repetitive defect, then use the table in this section to determine which part needs to be cleaned or replaced based on the measured distance between the repetitions of the defect.
NOTE: Spots can be dark or white (dropouts); bands can be all shapes and sizes.
Component | Distance between defects (mm) | Type of defects |
---|---|---|
Developing roller *1 | About 22 | Dropouts Dark, sharp bands |
Primary charging roller *1 | About 26 | Dropouts |
RS roller | About 29 | Dropouts |
Secondary transfer roller | About 47 | Dropouts Dirt on the back of page |
Fuser film | About 58 | Dropouts Dirt on page Loose toner |
Pressure roller | About 63 | Dirt on page Dirt on the back of page Loose toner |
ITB drive roller | About 76 | Spots |
Photosensitive drum *1 | About 95 | Dropouts Dirt on page |
*1 - The primary charging roller, photosensitive drum, and developing drum cannot be cleaned. If these rollers cause a repetitive defect, replace the corresponding cartridge, either the imaging-drum cartridge or the developing cartridge.