• Code: C2350
• Description: Toner suction fan's failure to turn. The fan lock signal remains HIGH for a predetermined continuous period of time while the fan is turning.
• Causes: • Toner suction fan (FM11) • Extension control board (EXCB) • Printer control board (PRCB)
• Remedy: 1 Check the connectors between FM11-relay CN62- PRCB CN23 for proper connection, and correct as necessary. 2 Check the connectors between PRCB CN10-EXCB CN1 for proper connection, and correct as necessary. 3 Check the fan for possible overload and correct as necessary. 4 FM11 operation check PRCB CN23-7 (REM) PRCB CN23-9 (LOCK) 5-C 5 Replace FM11 6 EXCB ICP1 conduction check 7 Replace EXCB 8 PRCB ICP20 conduction check 9 Replace PRCB

• Code: C2355
• Description: Transfer belt cleaner cooling fan’s failure to turn. The fan lock signal remains HIGH for a predetermined continuous period of time while the fan is turning.
• Causes: • Transfer belt cleaner cooling fan (FM2) • Printer control board (PRCB)
• Remedy: 1 Check the connector between FM2-relay CN115- PRCB CN13 for proper connection and correct as necessary. 2 Check the fan for possible overload and correct as necessary. 3 FM2 operation check PRCB CN13-8 (REM) PRCB CN13-10 (LOCK) bizhub C554e 25-C bizhub C454e 23-C 4 Replace FM2 5 PRCB ICP3 conduction check 6 Replace PRCB

• Code: C2414
• Description: Developing unit new article release. The status with the new unit is not cleared after the new developing unit is set.
• Causes: • Developing unit • Front side board (FRB) • Printer control board (PRCB)
• Remedy: 1 Reinstall developing unit 2 Check the connector between developing unit-FRB CN13 for proper connection and correct as necessary. 3 Check the connector between FRB CN1, CN3-PRCB CN7, CN9 for proper connection and correct as necessary. 4 Replace the developing unit 5 Replace FRB 6 Replace PRCB

• 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 higher 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 • Toner cartridge • Toner empty switch/K (PS31) • Toner bottle motor (M10) • Toner supply motor/K (M6) • Front side board (FRB) • Printer control board (PRCB)
• Remedy: 1 Perform image troubleshooting procedure if image density is low. 2 Reinstall developing unit 3 Reinstall toner cartridge 4 Check the connector between developing unit-FRB CN13 for proper connection and correct as necessary. 5 Check the connector between FRB CN1, CN3-PRCB CN7, CN9 for proper connection and correct as necessary. 6 M10 operation check PRCB CN14-1 to 4 17-C 7 M6 operation check PRCB CN14-5 to 8 17-C 8 If the toner empty sensor and its surroundings inside the sub hopper are dirtied with toner, clean them. 9 Replace the developing unit 10 Replace FRB 11 PRCB IC44, IC46 conduction check 12 Replace PRCB

• Code: C2558
• Description: Abnormally high toner density detected black TCR sensor. The TC ratio of the toner determined by the toner replenishment control is detected to be the predetermined value or over for consecutive times.
• Causes: • Developing unit • Toner cartridge • Front side board (FRB) • Printer control board (PRCB)
• Remedy: 1 Reinstall developing unit 2 Reinstall toner cartridge 3 Check the connector between developing unit-FRB CN13 for proper connection and correct as necessary. 4 Check the connector between FRB CN1, CN3-PRCB CN7, CN9 for proper connection and correct as necessary. 5 Replace the developing unit 6 Replace FRB 7 Replace PRCB

• Code: C255C
• Description: Black TCR sensor adjustment failure. TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Developing unit • Toner bottle motor (M10) • Toner supply motor/K (M6) • Front side board (FRB) • Printer control board (PRCB)
• Remedy: 1 Reinstall developing unit 2 Check the connector between developing unit-FRB CN13 for proper connection and correct as necessary. 3 Check the connector between FRB CN1, CN3-PRCB CN7, CN9 for proper connection and correct as necessary. 4 M10 operation check PRCB CN14-1 to 4 18-C 5 M6 operation check PRCB CN14-5 to 8 17 to 18-C 6 Replace the developing unit 7 Replace FRB 8 PRCB IC44, IC46 conduction check 9 Replace PRCB

• Code: C2564
• Description: Black TCR sensor failure. TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Developing unit • Front side board (FRB) • Printer control board (PRCB)
• Remedy: 1 Reinstall developing unit 2 Check the connector between developing unit-FRB CN13 for proper connection and correct as necessary. 3 Check the connector between FRB CN1, CN3-PRCB CN7, CN9 for proper connection and correct as necessary. 4 Replace the developing unit 5 Replace FRB 6 Replace PRCB

• Code: C2650
• Description: Main backup media access error. • The re-written data, which has been read out, checked and founded as error, is read out again and found as error. • The error was found when reading out the counter value. • MFP detects that the SSD board is not mounted
• Causes: • SSD board (SSDB) • MFP board (MFPB) • Printer control board (PRCB)
• Remedy: 1 Check the connector from SSDB to MFPB for proper connection and correct as necessary. 2 Check the harness from MFPB to PRCB for proper connection and correct as necessary. 3 Replace MFPB 4 Replace PRCB. 1. When the finisher or job separator has been installed, remove it once. 2. Check that the trouble code “C4802” appears and then display service mode. 3. Call the Enhanced Security to the screen. 4. Touch [Engine Data Backup]. 5. Touch [Engine Data Reflect Mode], and press the Start key. 6. Select [Yes], and press the Start key again. 7. Check that the result “OK” appears. 8. Turn OFF the main power switch and turn it ON again more than 10 seconds after. 9. Update the PRCB firmware. 10. Make the specified readjustments. 5 If the above actions do not solve the problem, contact KM.