| Problem | Possible Cause | Solution |
| Vertical black lines |
Defective toner cartridge |
Perform a halfway test to isolate the problem. Replace toner cartridge if necessary. |
| Vertical black lines |
Worn , failing fuser film
|
Perform a halfway test to isolate the problem. Check fuser film for tearing or wear. 1. Set the fuser to a lower temperature mode. 2. Replace the fuser if necessary.
|
| Vertical black lines |
Defective formatter generating a "video line"
|
Replace formatter if necessary
|
| Vertical black lines |
Faulty DC controller or high voltage power supply
|
Replace DC controller , high voltage if necessary
|
