• Code: C2350
• Description: Toner suction fan 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 (FM4) • MFP board (MFPB)
• Remedy: 1. Check the connector between FM4-relay CN46-MFPB CN15E for proper connection and correct as necessary. 2. Check the fan for possible overload and correct as necessary. 3. FM4 operation check • Control signal: MFPB CN15E-1 (REM), MFPB CN15E-3 (LOCK) • Location of electrical component: 16 to 17-C 4. Replace FM4. 5. MFPB F7E conduction check 6. Replace MFPB.

• Code: C2414
• Description: Developing unit/K new article release. The status with the new unit is not cleared after the new developing unit is set.
• Causes: • Developing unit/K • MFP board (MFPB)
• Remedy: 1. Reinstall developing unit/K. 2. Check the connector between the developing unit-relay CN15-MFPB CN17E for proper connection and correct as necessary. 3. Replace the developing unit/K. 4. Replace MFPB.

• 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 toner hopper.
• Causes: • Developing unit/K • Toner cartridge/K • Toner empty sensor/K (PS31) • Toner cartridge motor (M10) • Toner supply motor/K (M6) • 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 the developing unit-relay CN15-MFPB CN17E for proper connection and correct as necessary. 5. M10 operation check • Control signal: MFPB CN22E-5 to 8 • Location of electrical component: 20-J 6. M6 operation check • Control signal: MFPB CN22E-1 to 4 • Location of electrical component: 20-J 7. If the toner empty sensor and its surroundings inside the toner hopper are dirtied with toner, clean them. 8. Replace the developing unit/K. 9. MFPB F13E, F14E conduction check 10. Replace MFPB.

• 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/K • Toner cartridge/K • MFP board (MFPB)
• Remedy: 1. Reinstall developing unit/K. 2. Reinstall toner cartridge/K. 3. Check the connector between the developing unit-relay CN15-MFPB CN17E for proper connection and correct as necessary. 4. Replace the developing unit/K. 5. Replace MFPB.

• 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/K • Toner cartridge motor (M10) • Toner supply motor/K (M6) • MFP board (MFPB)
• Remedy: 1. Reinstall developing unit/K. 2. Check the connector between the developing unit-relay CN15-MFPB CN17E for proper connection and correct as necessary. 3. M10 operation check • Control signal: MFPB CN22E-5 to 8 • Location of electrical component: 20-J 4. M6 operation check • Control signal: MFPB CN22E-1 to 4 • Location of electrical component: 20-J 5. Replace the developing unit/K. 6. Replace MFPB.

• Code: C2564
• Description: Black TCR sensor failure. The TCR sensor input is 0. This detection is used for detecting disconnection of TCR sensor connector.
• Causes: • Developing unit/K • MFP board (MFPB)
• Remedy: 1. Reinstall developing unit/K. 2. Check the connector between the developing unit-relay CN15-MFPB CN17E for proper connection and correct as necessary. 3. Replace the developing unit/K. 4. Replace MFPB.

• 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. • The main body detects that the backup board (ERB) is not mounted.
• Causes: • Backup board (ERB) • MFP board (MFPB)
• Remedy: 1. Check the connector from ERB CN1-MFPB CN20E for proper connection and correct as necessary. 2. Replace ERB. 3. Replace MFPB. 4. If the above actions do not solve the problem, contact KM.

• Code: C2A14
• Description: Drum unit/K new release failure. The status with the new unit is not cleared after the new drum unit is set.
• Causes: • Drum unit/K • MFP board (MFPB)
• Remedy: 1. Clean the connection between the drum unit and the machine if dirty. 2. Reinstall the drum unit/K. 3. Check the connector between the drum unit-relay CN13-MFPB CN17E for proper connection and correct as necessary. 4. Replace the drum unit/K. 5. Replace MFPB.