• Code: 50.3
• Display: 50.3 Fuser Error
• Description: Abnormally high fuser temperature.
• Remedy: 1. Reinstall the fuser. Check the connector (J704) between the fuser and the product. If it is damaged, replace the fuser drive unit or fuser. 2. Reconnect the connector (J131A) on the DC controller PCA. 3. Replace the fuser.

• Code: 50.4
• Display: 50.4 Fuser Error
• Description: Fuser drive circuit is defective.
• Remedy: 1. Check the power source at the product location. NOTE: If the product does not meet the power requirement of 43 to 57Hz frequency, the fuser temperature control does not work correctly and this causes malfunction. 2. Reconnect the connector (J21) on the DC controller PCA. 3. Replace the low-voltage power supply unit.

• Code: 50.7
• Display: 50.7 Fuser Error
• Description: The fuser is defective (pressure release mechanism abnormality).
• Remedy: 1. Reconnect the connector (J181) on the DC controller PCA. 2. Run the sensor test in the sensor monitor mode to verify that the fuser pressure release sensor is functioning correctly. If it is not, replace the fuser pressure release sensor unit. 3. Check the fuser pressure release sensor flag. If it is damaged, replace the fuser. 4. Run the fuser pressure release drive test in the actuator drive mode to verify that the fuser motor is functioning correctly. If it is not, replace the fuser motor. 5. Replace the fuser.

• Code: 50.8
• Display: 50.8 Fuser Error
• Description: Abnormally low subthermistor fuser temperature error.
• Remedy: 1. Remove the fuser and remove any residual media in the fuser. 2. Reinstall the fuser. Check the connector (J704) between the fuser and the product. If it is damaged, replace the fuser drive unit or fuser. 3. Reconnect the connector (J131A) on the DC controller PCA and the connectors (J109, J110) on the power line between the low-voltage power supply unit and fuser. 4. Replace the fuser.

• Code: 50.9
• Display: 50.9 Fuser Error
• Description: Abnormally high subthermistor fuser temperature error.
• Remedy: 1. Reinstall the fuser. Check the connector (J704) between the fuser and the product. If it is damaged, replace the fuser drive unit or fuser. 2. Reconnect the connector (J131A) on the DC controller PCA. 3. Replace the fuser.

• Code: 51.20
• Display: 51.XX Error
• Description: The product has experienced an internal error with a laser scanner.
  black
• Remedy: 1. Turn the product off and then on. 2. Verify that the connectors J61 and J62 on the DC controller PCA are correctly seated. Also verify that the connectors on the laser scanner are correctly seated. 3. If the problem remains, replace the laser scanner.

• Code: 51.21
• Display: 51.XX Error
• Description: The product has experienced an internal error with a laser scanner.
  cyan
• Remedy: 1. Turn the product off and then on. 2. Verify that the connectors J61 and J62 on the DC controller PCA are correctly seated. Also verify that the connectors on the laser scanner are correctly seated. 3. If the problem remains, replace the laser scanner.

• Code: 51.22
• Display: 51.XX Error
• Description: The product has experienced an internal error with a laser scanner.
  magenta
• Remedy: 1. Turn the product off and then on. 2. Verify that the connectors J61 and J62 on the DC controller PCA are correctly seated. Also verify that the connectors on the laser scanner are correctly seated. 3. If the problem remains, replace the laser scanner.