Black Lines
| Laser printer print defects - Black lines parallel or perpendicular |  |
| Problem | Cause | Solution | How common* | Comments |
| black lines - parallel or perpendicular | Repetitive defect. If the lines are repeated at a consistent interval down the page, this is a repetitive defect | See the Repetitive Image Defect Ruler In service manual | 10 | |
| *On a scale of 1-10, how often this problem occurs (10 being most likely). | ||||
