Error codes konica minolta

Code: C2557
Description:
Abnormally low toner density detected black TCR sensor. When sampling data is determined in TC ratio calculation control, TCR sensor output is lower than a predetermined value for a predetermined number of times in a row even though there is toner in the sub hopper.
Causes:
• Developing unit/K • Toner cartridge/K • Toner empty sensor/K (PZS/K) • Toner supply motor/K (M12) • Toner cartridge motor /CK (M14) • Process drive board (PDB) • MFP board (MFPB)
Remedy:
1. Perform image troubleshooting procedure if image density is low. 2. Reinstall developing unit/K. 3. Reinstall toner cartridge/K. 4. Check the connector between M12-relay CN258-PDB CN8 for proper connection and correct as necessary. 5. Check the connector between M14-relay CN321-relay CN428-PDB CN7 for proper connection and correct as necessary. 6. Check the connector of M12, M14 for proper drive coupling and correct as necessary. 7. Check the connector between PZS/K-relay CN248-relay CN265-MFPB CN4E for proper connection and correct as necessary. 8. PZS/K I/O check, sensor check • Control signal: MFPB CN4E-12 (ON) • Location of electrical component: 17-C 9. M12 operation check (At this time, developing/drum unit must be non-installation.) • Control signal: PDB CN8-13 to 16 • Location of electrical component: 16-X 10. M14 operation check • Control signal: PDB CN7-1 to 4 • Location of electrical component: 17-P 11. Replace M12. 12. Replace M14. 13. If the toner empty sensor and its surroundings inside the sub hopper are dirtied with toner, clean them. 14. Replace the developing unit/K. 15. PDB F1 or F2 conduction check 16. Replace PDB. 17. Replace MFPB.