C2557 (bizhub 958/808)

Contents

Trouble type	C2557: Abnormally low toner density detected black TCR sensor
Rank	B
Trouble detection condition	When sampling data is determined in TC ratio calculation control, TCR sensor output is higher than a predetermined value for a predetermined number of times in a row even though there is toner in the sub hopper.
Trouble isolation	–
Relevant electrical parts	• Developing unit • Toner cartridge • Toner empty sensor/K (PZS/K) • Toner supply motor/K (M12) • Toner cartridge motor/CK (M14) • MFP board (MFPB)

 Procedure

1. Perform image troubleshooting procedure if image density is low.
2. Check the connector between M12-relay CN258-MFPB CN18E for proper connection and correct as necessary.
3. Check the connector between M14-relay CN321-relay CN428-MFPB CN19E for proper connection and correct as necessary.
4. Check the connector of M12 and M14 for proper drive coupling and correct as necessary.
5. Check the connector between PZS/K-relay CN253-MFPB CN27E for proper connection and correct as necessary.
6. PZS/K I/O check, sensor check
   • Control signal: MFPB CN27E<A>-11 (ON)
   • Location of electrical component: 17-C
7. M12 operation check (At this time, developing/drum unit must be non-installation.)
   • Control signal: MFPB CN18E-15 to 18
   • Location of electrical component: 15-K
8. M14 operation check
   • Control signal: MFPB CN19E-1 to 4
   • Location of electrical component: 2-K
9. Replace M12. (Part# A00JM12100)
10. Replace M14. (Part# 9314130021)
11. Reinstall developing unit.
12. Reinstall the toner cartridge. (958 Part# A8H5031 / 808 Part# A8H5030)
13. If the toner empty sensor and its surroundings inside the sub hopper are dirtied with toner, clean them.
14. Replace the developing unit. (Part# A8H403D)
15. MFPB F7E or IC80E conduction check
16. Replace MFPB. (Part# A796H02003)

NOTICE

• Link to the wiring diagram (bizhub 958/808/758, bizhub PRO 958)

Please search Knowledge Base articles and Bulletins as they may contain relevant information and updated Part information such as Part numbers.

K.3.8.13 (Link to the Field Service Manual)