Symptom: Vertical black bars appear on the copy

cause of the issue:

1. The optical part is dirty.
2. There is dust between the cleaning blade and the drum.
3. The blade of the cleaning blade is deformed.
4. The cleaning brush and the developing device inlet seal are deformed.

Solution: First, reduce the copy and try to see if the black bars move? If moving, check and clean the optical section and the dust glass to see if the movement disappears. Secondly, if the reduced copy black strip does not move, press the scraper release lever two or three times to clean the cleaning scraper if the black strip still appears. Check if the cutting edge of the cleaning blade is deformed? If it is deformed, it needs to be replaced or there is nothing else on the blade of the cleaning blade. Finally, if the cutting edge of the cleaning blade is not deformed, check if the drum charging roller is dirty, toner or other things affect the copying effect, if it is dirty, clean it, or replace the drum charging roller, such as the drum charging roller is not dirty. Check if the developing device inlet seal is deformed, and if so, replace the entire set of inlet seal plates and seals.