• Code: E020-04A2
• Description: Toner density sensor (Bk) output upper limit error. The toner density sensor output (Vsig_ind) is less than 247.
• Remedy: 1. Check the connection between the toner density sensor and the DC controller interface PCB. (Connector, Breaking (shorting)) <Y> sensor side: J7133, J8028, J8087 PCB side: J1240, J8085 <M> sensor side: J7134, J8029, J8088 PCB side: J1240, J8085 <C> sensor side: J7135, J8030, J8089 PCB side: J1240, J8086 <Bk> sensor side: J7146, J8015, J8117 PCB side: J1240, J8086 2. Check whether disconnection or shorting of the toner density sensor occurs or not. 3. Replace the developing assembly.

• Code: E020-04C2
• Description: Patch (Y) sampling error. The variation before average patch P wave light intensity is more than 100.
• Remedy: 1. Check whether the developing assembly and the drum unit are properly installed. 2. Clean the patch sensor. 3. Check the connection between the patch sensor and the DC controller interface PCB. (Connector, Breaking (shorting)) Sensor side: J7412, J8035 PCB side: J1242 4. Clean or replace the ITB. Check whether the ITB belt is dirty or not. If it is dirty, perform cleaning with the following service mode. COPIER>FUNCTION>CLEANING>TBLT-CLN If it is assumed that this error occurred due to scratches on the ITB, replace the ITB. 5. Replace the patch sensor unit. 6. Replace the developing assembly. (Check whether there is not uneven coating on the developing sleeve.)

• Code: E021-0101
• Description: Developing sleeve drive motor (Y) error. The lock signal of the developing sleeve drive motor (Y) (M20) cannot be detected within a specified period. Connector disconnected, breaking (shorting) Failure of the developing assembly (Sleeve overloaded) Failure of the DC controller interface PCB (Fuse (FU5 burns)) Failure of the developing sleeve motor
• Remedy: 1. Check the connection between the developing sleeve drive motor (Y) (UN20) and the DC controller interface PCB (UN2). (Connection of the connector, Breaking (shorting)) Motor side: J7535, J8034 PCB side: J1220 2. Replace the developing assembly (Y). 3. Replace the DC controller interface PCB (UN2). 4. Replace the developing sleeve drive motor (Y).

• Code: E021-0102
• Description: Developing sleeve drive motor (Y) error. Lock signal of Developing sleeve drive motor (Y)(M20) cannot be detected for the specified time after first detection Connector disconnected, breaking (shorting) Failure of the developing assembly (Sleeve overloaded) Failure of the DC controller interface PCB (Fuse (FU5 burns)) Failure of the developing sleeve motor
• Remedy: 1. Check the connection between the developing sleeve drive motor (Y) (UN20) and the DC controller interface PCB (UN2). (Connection of the connector, Breaking (shorting)) Motor side: J7535, J8034 PCB side: J1220 2. Replace the developing assembly (Y). 3. Replace the DC controller interface PCB (UN2). 4. Replace the developing sleeve drive motor (Y).

• Code: E021-0201
• Description: Developing sleeve drive motor (M) error. The lock signal of the developing sleeve drive motor (M) (M22) cannot be detected within a specified period. Connector disconnected, breaking (shorting) Failure of the developing assembly (Sleeve overloaded) Failure of the DC controller interface PCB (Fuse (FU5 burns)) Failure of the developing sleeve motor
• Remedy: 1. Check the connection between the developing sleeve drive motor (M) (UN22) and the DC controller interface PCB (UN2). (Connection of the connector, Breaking (shorting)) Motor side: J7536, J8034 PCB side: J1220 2. Replace the developing assembly (M). 3. Replace the DC controller interface PCB (UN2). 4. Replace the developing sleeve drive motor (M).

• Code: E021-0202
• Description: Developing sleeve drive motor (M) error. Lock signal of Developing sleeve drive motor (M)(M22) cannot be detected for the specified time after first detection Connector disconnected, breaking (shorting) Failure of the developing assembly (Sleeve overloaded) Failure of the DC controller interface PCB (Fuse (FU5 burns)) Failure of the developing sleeve motor
• Remedy: 1. Check the connection between the developing sleeve drive motor (M) (UN22) and the DC controller interface PCB (UN2). (Connection of the connector, Breaking (shorting)) Motor side: J7536, J8034 PCB side: J1220 2. Replace the developing assembly (M). 3. Replace the DC controller interface PCB (UN2). 4. Replace the developing sleeve drive motor (M).

• Code: E021-0301
• Description: Developing sleeve drive motor (C) error. The lock signal of the developing sleeve drive motor (C) (M24) cannot be detected within a specified period. Connector disconnected, breaking (shorting) Failure of the developing assembly (Sleeve overloaded) Failure of the DC controller interface PCB (Fuse (FU5 burns)) Failure of the developing sleeve motor
• Remedy: 1. Check the connection between the developing sleeve drive motor (C) (UN24) and the DC controller interface PCB (UN2). (Connection of the connector, Breaking (shorting)) Motor side: J7537, J8034 PCB side: J1220 2. Replace the developing assembly (C). 3. Replace the DC controller interface PCB (UN2). 4. Replace the developing sleeve drive motor (C).

• Code: E021-0302
• Description: Developing sleeve drive motor (C) error. Lock signal of Developing sleeve drive motor (C)(M24) cannot be detected for the specified time after first detection Connector disconnected, breaking (shorting) Failure of the developing assembly (Sleeve overloaded) Failure of the DC controller interface PCB (Fuse (FU5 burns)) Failure of the developing sleeve motor
• Remedy: 1. Check the connection between the developing sleeve drive motor (C) (UN24) and the DC controller interface PCB (UN2). (Connection of the connector, Breaking (shorting)) Motor side: J7537, J8034 PCB side: J1220 2. Replace the developing assembly (C). 3. Replace the DC controller interface PCB (UN2). 4. Replace the developing sleeve drive motor (C).