| Problem | Possible Cause | Solution |
|---|
| Vertical black lines |
Defective toner cartridge |
Very common -- Install another toner cartridge or perform a halfway test to isolate the problem. Replace toner cartridge if necessary. |
| Vertical black lines |
Worn , failing fuser film |
Somewhat common -- Perform a halfway test to isolate the problem. Check fuser film for tearing or wear. Replace the fuser if necessary. |
| Vertical black lines |
Defective formatter generating a "video line" |
Less common -- Replace formatter if necessary |
| Vertical black lines |
Faulty DC controller or high voltage power supply |
Less common -- Replace DC controller , high voltage if necessary |
