1. Toner cartridge leakage: In addition to shell damage, it is usually due to the accumulation of powder on the magnetic stick in the toner cartridge during transportation or during use by some customers. The solution is simple, just turn the drum core a few times in the same direction.

2. A vertical underworld with the same width above 1 cm appears on the printed document and the drum core at the same time. Generally, customers also think that it is powder leakage: this is a problem with the scraper, causing the scraping on the drum core to be dirty.

3. Horizontal underworld appears in the printed document: usually the magnetic stick in the toner cartridge has accumulated powder, just turn it around a few times.

4. There are vertical thin black lines on the printed document: usually the scraper and the small scraper on the side of the scraper are stuck with dirt or paper scraps.

5. If there is obvious bottom ash on the printed document: usually there is a problem with the drum core or toner.

6. The color of the printed document is uneven, and there is a famous white line: Can you see the toner from the outside of the magnetic stick? If you see some powder on the magnetic stick and no powder in some places, it means that the toner cartridge is used up.

7. If the printer prints a blank sheet of paper: first check if there is a problem with the printer. If there is no problem, it means that there is a problem with the toner cartridge during assembly.