Horizontal Black Lines
| Laser printer print defects - Horizontal Black Lines |  |
| Problem | Cause | Solution | How common* | Comments |
| Horizontal black lines | Defective laser scanner assembly or engine controller board | 1. See the 'Repetitive defect ruler' 2. Reseat connectors on the laser scanner and engine controller board. 3. Replace the laser/scanner assembly followed by the engine controller board, if necessary | 8 | |
| *On a scale of 1-10, how often this problem occurs (10 being most likely). | ||||
