• Code: C4801
• Description: Main unit board failure MFP detects simultaneous replacement of multiple boards.
• Causes: • SSD board (SSDB) • Printer control board (PRCB)
• Remedy: 1 Reinstall the old PRCB. 2 If the above actions do not solve the problem, contact KM.

• Code: C4802
• Description: Main unit backup data miscompare The replacement of the printer control board is detected.
• Causes: Printer control board (PRCB)
• Remedy: 1 1. When the finisher or job separator has been installed, remove it once. 2. Call the Enhanced Security in Service Mode to the screen. 3. Touch [Engine Data Backup]. 4. Touch [Engine Data Reflect mode], and press the Start key. 5. Select [Yes], and press the Start key again. 6. Check that the result “OK” appears. 7. Turn OFF the main power switch and turn it ON again more than 10 seconds after. 2 Update the PRCB firmware. 3 If the above actions do not solve the problem, contact KM.

• Code: C5104
• Description: Transfer belt motor's failure to turn The motor lock signal remains HIGH for a predetermined continuous period of time while the motor is turning.
• Causes: • Transfer belt unit • Transfer belt motor (M1) • Printer control board (PRCB)
• Remedy: 1 Check the connector between M1-PRCB CN21 for proper connection and correct as necessary. 2 Check the transfer belt for proper drive coupling and correct as necessary. 3 Check the drive gear of the transfer belt unit for rotation and correct any faulty rotation. 4 M1 operation check PRCB CN21-3 (REM) PRCB CN21-6 (LOCK) 17-K 5 Replace M1 6 Replace the transfer belt unit. 7 PRCB ICP7 or ICP18 conduction check 8 Replace PRCB

• Code: C5105
• Description: Transfer belt motor's turning at abnormal timing The motor lock signal remains LOW for a predetermined continuous period of time while the motor remains stationary.
• Causes: • Transfer belt unit • Transfer belt motor (M1) • Printer control board (PRCB)
• Remedy: 1 Check the connector between M1-PRCB CN21 for proper connection and correct as necessary. 2 Check the transfer belt for proper drive coupling and correct as necessary. 3 Check the drive gear of the transfer belt unit for rotation and correct any faulty rotation. 4 M1 operation check PRCB CN21-3 (REM) PRCB CN21-6 (LOCK) 17-K 5 Replace M1 6 Replace the transfer belt unit. 7 PRCB ICP7 or ICP18 conduction check 8 Replace PRCB

• Code: C5304
• Description: IH power supply 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: • IH power supply cooling fan (FM10) • Printer control board (PRCB)
• Remedy: 1 Check the connector between FM10-relay CN293- PRCB CN5 for proper connection and correct as necessary. 2 Check the fan for possible overload and correct as necessary. 3 FM10 operation check PRCB CN5-1 (DRIVE) PRCB CN5-3 (LOCK) 9-K 4 Replace FM10 5 PRCB ICP24 conduction check 6 Replace PRCB

• Code: C5306
• Description: IH coil 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: • IH coil cooling fan (FM3) • Printer control board (PRCB)
• Remedy: 1 Check the connector between FM3-relay CN324- PRCB CN2 for proper connection and correct as necessary. 2 Check the fan for possible overload and correct as necessary. 3 FM3 operation check PRCB CN2-7 (DRIVE) PRCB CN2-9 (LOCK) 3-K 4 Replace FM3 5 Replace PRCB

• Code: C5351
• Description: DC power supply 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: • DC power supply cooling fan (FM9) • DC power supply (DCPU) • Printer control board (PRCB)
• Remedy: 1 Check the connector between FM9-relay CN333- PRCB CN38 for proper connection and correct as necessary. 2 Check the fan for possible overload and correct as necessary. 3 FM9 operation check PRCB CN38-1 (DRIVE) PRCB CN38-3 (LOCK) 19-K 4 Replace FM9 5 PRCB ICP3 conduction check 6 Replace DCPU 7 Replace PRCB

• Code: C5354
• Description: Ozone ventilation fan's failure to turn The fan lock signal remains HIGH for a predetermined continuous period of time while the fan is turning.
• Causes: • Ozone ventilation fan motor (FM6) • Printer control board (PRCB)
• Remedy: 1 Check the connector between FM6-relay CN322- PRCB CN1 for proper connection and correct as necessary. 2 Check the fan for possible overload and correct as necessary. 3 FM6 operation check PRCB CN1-6 (DRIVE) PRCB CN1-8 (LOCK) 7-K 4 Replace FM6 5 Replace PRCB