• Code: 7400
• Description: The developer unit is not installed or not installed properly
  Failed to detect the voltage to identify the developer.
• Causes: The developer unit is not installed. The developer connector is not properly inserted in the printer. Defective developer unit. Defective engine board (KP-1081).

• Code: 7410
• Description: The drum unit is not installed or not installed properly
  EEPROM communication error or the drum ID was not identified.
• Causes: The drum unit is not installed. The drum unit connector is not properly inserted in the printer. Defective drum unit. Defective engine board (KP-1081)

• Code: 8000
• Description: Non-supported device is installed as an optional exit
  Serial communication detected that a non-supported bulk paper stacker HS-8E has been installed.
• Causes: A non-supported bulk paper stacker HS-8E is installed.

• Code: F0
• Description: Main board or LCD controller board error
  Communication is failed between the LCD controller board (KP-1079) and the main board.has
• Causes: Defective system DIMM [board KP- 1059*1/893*2*3]. Defective main board (KP-1053/ 1033).

• Code: F010
• Description: System DIMM [board] error
  Checksum failed with system DIMM [board KP-1059/893] on the main board.
• Causes: LCD controller board (KP-1079). Defective system DIMM [board KP- 1059*1/893*2*3]. Improper system DIMM [board KP- 1059*1/893*2*3] insertion to system DIMM slot on the main board (KP-1053/ 1033

• Code: F020
• Description: Main or expanded memory error
  Checksum failed with main memory (RAM) on the main board or expanded memory (DIMM).
• Causes: Defective system main memory (RAM) on the main board (KP- 1059*1/893*2*3). Defective main board (KP-1053/ 1033). Defective expanding memory (DIMM) on the main board (KP- 1053/1033)

• Code: F040
• Description: Communication error
  Communication between the engine board and the main board is failed.
• Causes: Defective gate array (U02) on the main board. Connector failure between the engine board (KP- 1081) and main board (KP-1053/ 1033).

• Code: F070
• Description: Flash ROM error
  CPU U1 of engine board could not write data failed to flash ROM U2. Write sequence to flash ROM is not successful. Verify error. (Written data does not match the original data.)
• Causes: Overrun in the engine system, deactivating the program flash ROM (U2) on the engine board (KP- 1081). Defective CPU U1 or gate array U7 or flash ROM U2 on the engine board (KP-1081).