• Code: E020-0491
• Description: Error in Bk Developing Assembly
  Error in signal upper limit with ATR sampling detected value
• Remedy: 1. Check toner leak from the Toner Buffer Unit. 2. Check toner level in the Toner Container. 3. Replace the Developing Assembly. 4. Check short-circuit of the harness with the Toner Buffer Supply Sensor (PS4).

• Code: E020-04B0
• Description: Error in Bk Developing Assembly
  TD ratio lower limit error at the time of print sequence (Large amount of toner in the Developing Assembly)
• Remedy: Go through the following: DISPLAY > DENS > DENS-K; if DENS-K is slightly higher than 5.0%, output 10 sheets of solid image with the color causing the error (to reduce T/D ratio). See the Service Mode again to see if the problem is improved. Remedy is complete if it’s improved. If not, perform the following remedy work. 1. Check if the ATR Sensor (TS8) Connector is disconnected. 2. Check short-circuit of the ATR Sensor Harness. 3. Replace the Developing Assembly.

• Code: E020-04B1
• Description: Error in Bk Developing Assembly
  TD ratio upper limit error at the time of print sequence (Small amount of toner in the Developing Assembly)
• Remedy: 1. Output 10 sheets of white (blank) sheets (to increase T/D ratio). 2. Check toner leak from the Toner Buffer Unit. 3. Check toner level in the Toner Container. 4. Replace the Developing Assembly. 5. Check short-circuit of the harness of the Toner supply sensor (PS4).

• Code: E021-0100
• Description: Error in Y Developing Motor
  The motor failed to rotate at the specified speed.
• Remedy: 1. Check the load applied to the Developing Assembly (turn the gear with your hand to check if the load is appropriate. If the load is too much, replace the Developing Assembly). 2. Select the following in Service Mode: COPIER > FUNCTION > PART-CHK > MTR; and turn M5 to check the drive of the Developing Motor. If it’s not rotating properly, check the harness (to see if the harness is caught, disconnected or physically removed). 3. (If the above measures do not solve the problem,) replace the Drum Driver PCB (UN4).

• Code: E021-0200
• Description: Error in M Developing Motor
  The motor failed to rotate at the specified speed.
• Remedy: 1. Check the load applied to the Developing Assembly (turn the gear with your hand to check if the load is appropriate. If the load is too much, replace the Developing Assembly). 2. Select the following in Service Mode: COPIER > FUNCTION > PART-CHK > MTR; and turn M6 to check the drive of the Developing Motor. If it’s not rotating properly, check the harness (to see if the harness is caught, disconnected or physically removed). 3. (If the above measures do not solve the problem,) replace the Drum Driver PCB (UN4).

• Code: E021-0300
• Description: Error in C Developing Motor
  The motor failed to rotate at the specified speed.
• Remedy: 1. Check the load applied to the Developing Assembly (turn the gear with your hand to check if the load is appropriate. If the load is too much, replace the Developing Assembly). 2. Select the following in Service Mode: COPIER > FUNCTION > PART-CHK > MTR; and turn M7 to check the drive of the Developing Motor. If it’s not rotating properly, check the harness (to see if the harness is caught, disconnected or physically removed). 3. (If the above measures do not solve the problem,) replace the Drum Driver PCB (UN4).

• Code: E021-0400
• Description: Error in Bk Developing Motor
  The motor failed to rotate at the specified speed.
• Remedy: 1. Check the load applied to the Developing Assembly (turn the gear with your hand to check if the load is appropriate. If the load is too much, replace the Developing Assembly). 2. Select the following in Service Mode: COPIER > FUNCTION > PART-CHK > MTR; and turn M8 to check the drive of the Developing Motor. If it’s not rotating properly, check the harness (to see if the harness is caught, disconnected or physically removed). 3. (If the above measures do not solve the problem,) replace the Drum Driver PCB (UN4).

• Code: E025-0100
• Description: Error in lock of the Y Toner Container Motor
  The Y Toner Container Motor is detected to be locked / lock detection.
• Remedy: 1. Use the attached tool to manually rotate the Main Drive Unit to check the operation (by comparing with other color, etc.) If the manual rotating operation results in NG, perform the following because it’s due to mechanical overload. If there is no problem, go to step 5. 2. Remove the Delivery Tray to check the position of the projection attached at the back of the gear in the Hopper Assembly. Compare with the gear that works properly. If the position of the projection is displaced, check the following. Check the lever to open/close the Toner Small Cover (to see if the operation is smooth, no damage with the lever, the lever works OK (no wrong move to up/down). If the lever is faulty, replace the lever. 3. Remove the Main Drive Unit to check the unit (to see damage, etc.) If it’s results in NG, replace the Main Drive Unit. 4. Manually turn the gear on the cam in the hopper unit to check the rotation. If it’s results in NG, replace the Set-on Hopper Unit. 5. (If the above measures do not solve the problem) Replace the Toner Container Motor (M9). Replace the Drum Driver PCB (UN4).