Code :

Code: F2 71
Description: Developing unit improper cartridge detection (Cyan)
Causes: When detecting the normal CRUM of the cartridge, improper data are detected in the CRUM contents.
Remedy: Case 1 Cause Insertion of an improper cartridge. Developing unit trouble Check & Remedy Replace the developing unit.

Code: F2 72
Description: Developing unit improper cartridge detection (Magenta)
Causes: When detecting the normal CRUM of the cartridge, improper data are detected in the CRUM contents.
Remedy: Case 1 Cause Insertion of an improper cartridge. Developing unit trouble Check & Remedy Replace the developing unit.

Code: F2 73
Description: Developing unit improper cartridge detection (Yellow)
Causes: When detecting the normal CRUM of the cartridge, improper data are detected in the CRUM contents.
Remedy: Case 1 Cause Insertion of an improper cartridge. Developing unit trouble Check & Remedy Replace the developing unit.

Code: F2 74
Description: Developing unit CRUM trouble (Black)
Causes: CRUM read/write error
Remedy: Case 1 Cause Improper connection or disconnection of the connector and the harness between the PCU and the CRUM. Check & Remedy Check the connector and the harness between the PCU and the CRUM. Case 2 Cause Developing unit trouble Check & Remedy Replace the developing unit. Case 3 Cause Control PWB (PCU) trouble Check & Remedy Replace the PCU PWB.

Code: F2 75
Description: Developing unit CRUM trouble (Cyan)
Causes: CRUM read/write error
Remedy: Case 1 Cause Improper connection or disconnection of the connector and the harness between the PCU and the CRUM. Check & Remedy Check the connector and the harness between the PCU and the CRUM. Case 2 Cause Developing unit trouble Check & Remedy Replace the developing unit. Case 3 Cause Control PWB (PCU) trouble Check & Remedy Replace the PCU PWB.

Code: F2 76
Description: Developing unit CRUM trouble (Magenta)
Causes: CRUM read/write error
Remedy: Case 1 Cause Improper connection or disconnection of the connector and the harness between the PCU and the CRUM. Check & Remedy Check the connector and the harness between the PCU and the CRUM. Case 2 Cause Developing unit trouble Check & Remedy Replace the developing unit. Case 3 Cause Control PWB (PCU) trouble Check & Remedy Replace the PCU PWB.

Code: F2 77
Description: Developing unit CRUM trouble (Yellow)
Causes: CRUM read/write error
Remedy: Case 1 Cause Improper connection or disconnection of the connector and the harness between the PCU and the CRUM. Check & Remedy Check the connector and the harness between the PCU and the CRUM. Case 2 Cause Developing unit trouble Check & Remedy Replace the developing unit. Case 3 Cause Control PWB (PCU) trouble Check & Remedy Replace the PCU PWB.

Code: F2 78
Description: Trouble of image density sensor for registration (Transfer belt surface reflection ratio abnormality)
Causes: Before starting registration, the transfer belt surface is scanned with the image density sensor to adjust the sensor gain so that the output becomes a fixed value. However, when the sensor gain is changed, the value is not within the specified range.
Remedy: Case 1 Cause Image density sensor trouble, disconnection of the harness between the PCU PWB and the image density sensor, dirt on the image density sensor. Check & Remedy Check the sensor and the harness. Case 2 Cause Calibration plate solenoid operation trouble Check & Remedy Check the calibration plate solenoid operation. Case 3 Cause Insufficient cleaning of the transfer belt. Check & Remedy Check the transfer belt surface.