1. The printed document and the drum core appear at the same time in the longitudinal width of more than 1 cm at the same time: This is a problem with the scraper, causing the powder on the stick core to be dirty.

2. Long black stripes appear on the printed document: usually the scraper and the small scraper on the side of the scraper are stuck with dirt or paper scraps.

3. A horizontal underworld appears in the print file: usually the magnetic sticks in the toner cartridge have accumulated powder, and it can be rotated a few times.

4. If there is obvious background gray on the printed file: usually there is something wrong with the drum core or toner.

5. The color of the printed file is uneven, and the famous white road: Can you still see the toner when you look at the magnetic stick from the outside?

6. If the printer prints a blank piece of paper: first check if there is any problem with the printer. If there is no problem, it means that there is something wrong with the toner cartridge during assembly.