Misformed Image; Repetitive Image Defects Ruler - Canon imageCLASS LBP6780dn Service Manual

5
Troubleshooting > Corrective Actions > Image Defects > Repetitive image defects ruler

■ Misformed image

F-5-14
Image is misformed
Cause
1) Poor contact exists to the connector on the
laser scanner unit
2) Poor contact exists to the connector on the
Main Controller
3) The laser scanner unit is defective

■ Repetitive image defects ruler

Component Distance
between
defects (mm)
Registration roller About 44
Primary charging roller About 38
Photosensitive drum About 94
Developing roller About 50
Transfer roller About 43
Fixing film unit About 76
Pressure roller About 77
5 Troubleshooting > Corrective Actions > Image Defects > Repetitive image defects ruler
Solution
Reconnect the connectors: J12 and J100
Reconnect the connectors: J1505 and J1702
Replace the laser scanner unit.
Image defects
Dirt Dropouts Dirt on back Loose toner
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T-5-14
T-5-15
5-6
5-6