• Code: 7101
• Description: Toner sensor error (Black) For a certain period of time, the sensor output value is less than 0.1V, or more than 3.2V.
• Remedy: Toner container 1. Check that the toner container is properly installed, and if necessary, re-install. 2. Check that the toner supply inlet of the toner container can be opened by the lever operation. 3. Replace the toner container.
  Toner Sensor 1. Confirm that the connector of the developer unit is firmly connected, and if necessary, push the unit all the way in. Toner sensor - Unit relay PWB Unit relay PWB - Main/Engine PWB(YC7) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Check if the gears and spirals in the developer unit rotate smoothly. 4. Replace the developer unit.
  Toner Solenoid 1. Check that the toner solenoid is properly attached. 2. Check if the couplings and gears can rotate or if they are not unusually loaded, and if necessary, replace. 3. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Toner solenoid - container relay PWB (YC3) 4. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 5. Change the toner solenoid.
  Unit relay PWB Replace the unit relay PWB.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7102
• Description: Toner sensor error (Cyan) For a certain period of time, the sensor output value is less than 0.1V, or more than 3.2V.
• Remedy: Toner container 1. Check that the toner container is properly installed, and if necessary, re-install. 2. Check that the toner supply inlet of the toner container can be opened by the lever operation. 3. Replace the toner container.
  Toner Sensor 1. Confirm that the connector of the developer unit is firmly connected, and if necessary, push the unit all the way in. Toner sensor - Unit relay PWB Unit relay PWB - Main/Engine PWB(YC7) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Check if the gears and spirals in the developer unit rotate smoothly. 4. Replace the developer unit.
  Toner Solenoid 1. Check that the toner solenoid is properly attached. 2. Check if the couplings and gears can rotate or if they are not unusually loaded, and if necessary, replace. 3. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Toner solenoid - container relay PWB (YC3) 4. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 5. Change the toner solenoid.
  Unit relay PWB Replace the unit relay PWB.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7103
• Description: Toner sensor error (Magenta) For a certain period of time, the sensor output value is less than 0.1V, or more than 3.2V.
• Remedy: Toner container 1. Check that the toner container is properly installed, and if necessary, re-install. 2. Check that the toner supply inlet of the toner container can be opened by the lever operation. 3. Replace the toner container.
  Toner Sensor 1. Confirm that the connector of the developer unit is firmly connected, and if necessary, push the unit all the way in. Toner sensor - Unit relay PWB Unit relay PWB - Main/Engine PWB(YC7) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Check if the gears and spirals in the developer unit rotate smoothly. 4. Replace the developer unit.
  Toner Solenoid 1. Check that the toner solenoid is properly attached. 2. Check if the couplings and gears can rotate or if they are not unusually loaded, and if necessary, replace. 3. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Toner solenoid - container relay PWB (YC3) 4. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 5. Change the toner solenoid.
  Unit relay PWB Replace the unit relay PWB.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7104
• Description: Toner sensor error (Yellow) For a certain period of time, the sensor output value is less than 0.1V, or more than 3.2V.
• Remedy: Toner container 1. Check that the toner container is properly installed, and if necessary, re-install. 2. Check that the toner supply inlet of the toner container can be opened by the lever operation. 3. Replace the toner container.
  Toner Sensor 1. Confirm that the connector of the developer unit is firmly connected, and if necessary, push the unit all the way in. Toner sensor - Unit relay PWB Unit relay PWB - Main/Engine PWB(YC7) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Check if the gears and spirals in the developer unit rotate smoothly. 4. Replace the developer unit.
  Toner Solenoid 1. Check that the toner solenoid is properly attached. 2. Check if the couplings and gears can rotate or if they are not unusually loaded, and if necessary, replace. 3. Confirm that the wiring connector is firmly connected, and if necessary, connect the connector all the way in. Toner solenoid - container relay PWB (YC3) 4. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 5. Change the toner solenoid.
  Unit relay PWB Replace the unit relay PWB.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7200
• Description: Broken inner thermistor wire (Developer) The sensor input sampling value is greater than the reference value. (After detection, controlled at 25 °C/77.0 °F)
• Remedy: Developer unit BK 1. Confirm that the connector of the developer unit BK is firmly connected, and if necessary, push the unit all the way in. Toner sensor BK - Unit relay PWB (YC9) Unit relay PWB - Main/Engine PWB(YC7) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Replace the developer unit BK.
  Unit relay PWB Replace the unit relay PWB.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7210
• Description: Short-circuited inner thermistor (Developer) The sensor input sampling value is less than the reference value. (After detection, controlled at 25 °C/77.0 °F)
• Remedy: Developer unit BK 1. Confirm that the connector of the developer unit BK is firmly connected, and if necessary, push the unit all the way in. Toner sensor BK - Unit relay PWB (YC9) Unit relay PWB - Main/Engine PWB(YC7) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Replace the developer unit BK.
  Unit relay PWB Replace the unit relay PWB.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7221
• Description: Broken inner thermistor wire (LSU) The sensor input sampling value is greater than the reference value. (After detection, controlled at 25 °C/77.0 °F)
• Remedy: Laser scanner unit (LSU) 1. Confirm that the wiring connector of the LSU is firmly connected, and if necessary, connect the connector all the way in. LSU - Main/Engine PWB (YC21) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Replace the LSU.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.

• Code: 7231
• Description: Short-circuited inner thermistor (LSU) The sensor input sampling value is less than the reference value. (After detection, controlled at 25 °C/77.0 °F)
• Remedy: Laser scanner unit (LSU) 1. Confirm that the wiring connector of the LSU is firmly connected, and if necessary, connect the connector all the way in. LSU - Main/Engine PWB (YC21) 2. If the wire is disconnected, short-circuited or has a ground fault, or the connector pin is deformed, replace the wire. 3. Replace the LSU.
  Main/Engine PWB 1. Check the engine firmware and upgrade to the latest version if necessary. 2. Replace the main/engine PWB.