1. The photosensitive drum layer or drum gear is defective
If the photosensitive drum layer or drum gear of the toner cartridge is defective, the toner cartridge is basically scrapped and can no longer be used. At this time, only a new toner cartridge can be replaced.
2. The magnetic roller cover, magnetic roller coating, sheath, and bias contact points are defective
If the magnet roller cover, magnet roller coating, sheath, or bias contact point is defective, check the relevant position and replace or clean the bias contact point.
3. The transfer roller is defective
If the transfer roller is defective, just replace the transfer roller.
4. There is a problem with the high-voltage power supply
If there is a problem with the high-voltage power supply, the high-voltage power supply needs to be repaired.