• Code: 2557
• 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 toner cartridge.
• Causes: • Imaging unit/C,M,Y,K • Toner supply motor/YM (M5) • Toner supply motor/CK (M6) • Printer control board (PRCB)
• Remedy: 1 Perform image troubleshooting procedure if image density is low. - - 2 Reinstall the imaging unit - - 3 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 4 M5, M6 operation check PRCB CN22-1 to 4 (M5) PRCB CN22-5 to 8 (M6) 7-I 7-K 5 Replace the imaging unit - - 6 PRCB F5 conduction check - - 7 Replace PRCB

• Code: 2558
• Description: Abnormally high toner density detected black TCR sensor
  TC ratio in the imaging unit, which is determined by toner replenishing amount control mechanism, is a predetermined value or more for a given number of times consecutively
• Causes: • Imaging unit/C,M,Y,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB

• Code: 2559
• Description: Cyan TCR sensor adjustment failure
  TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Imaging unit/Y,M,C,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB

• Code: 255A
• Description: Magenta TCR sensor adjustment failure
  TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Imaging unit/Y,M,C,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB

• Code: 255B
• Description: Yellow TCR sensor adjustment failure
  TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Imaging unit/Y,M,C,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB

• Code: 255C
• Description: Black TCR sensor adjustment failure
  TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Imaging unit/Y,M,C,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB

• Code: 2561
• Description: Cyan TCR sensor failure
  TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Imaging unit/Y,M,C,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB

• Code: 2562
• Description: Magenta TCR sensor failure
  TCR sensor automatic adjustment does not function properly, failing to adjust to an appropriate value.
• Causes: • Imaging unit/Y,M,C,K • Printer control board (PRCB)
• Remedy: 1 Reinstall imaging unit - - 2 Check the connector between imaging unit-PRCB CN18, CN19 for proper connection and correct as necessary. - - 3 Replace the imaging unit - - 4 Replace PRCB