• Code: 7101
• Description: Toner sensor error
  Sensor output value of 60 or less or 944 or more continued for 3 s.
• Causes: Failure of locking the developer waste slot at setup. Toner sensor. Toner motor. Engine PWB.
• Remedy: Failure of locking the developer waste slot at setup. If an abnormal noise is heard, check that the developer ejection outlet is released and, if not, release the outlet.
  Toner sensor 1. Check the toner sensor output by U155. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Toner sensor and Front PWB (YC7) Front PWB (YC2) and Engine PWB (YC8) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Check that the gears of the Developer unit are not damaged and the spiral can rotate. 5. Replace the Developer unit.
  Toner motor 1. Draw out the toner container and execute U135 to check the toner motor operation. 2. Check the drive gear can rotate or 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 motor and Engine PWB (YC27) 4. If the wiring is disconnected, shorted or grounded, replace the wiring. 5. Replace the Toner motor.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7200
• Description: Broken outer temperature sensor 2 wire
  The sensor input sampling is greater than 230.
• Causes: Outer temperature sensor 2. Front PWB. Engine PWB.
• Remedy: Outer temperature sensor 2 1. Confirm Ext/Int is displayed by U139 temperature and humidity. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Outer temperature sensor 2 and Front PWB (YC8) Front PWB (YC2) and Engine PWB (YC8) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the outer temperature sensor 2.
  Front PWB Replace the front PWB.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7210
• Description: Short-circuited outer temperature sensor 2
  The sensor input sampling is less than 69.
• Causes: Outer temperature sensor 2. Front PWB. Engine PWB.
• Remedy: Outer temperature sensor 2 1. Confirm Ext/Int is displayed by U139 temperature and humidity. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Outer temperature sensor 2 and Front PWB (YC8) Front PWB (YC2) and Engine PWB (YC10) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the outer temperature sensor 2.
  Front PWB Replace the front PWB
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7221
• Description: Broken LSU thermistor wire
  The sensor input sampling is greater than 230.
• Causes: LSU thermistor. LSU relay PWB. Engine PWB.
• Remedy: LSU thermistor 1. Confirm LSU is displayed by U139 temperature and humidity. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Laser scanner unit and LSU relay PWB (YC3) LSU relay PWB (YC2) and Engine PWB (YC11) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the laser scanner unit.
  LSU relay PWB REPLACE the LSU relay PWB.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7231
• Description: Short-circuited LSU thermistor K
  The sensor input sampling is less than 69.
• Causes: LSU thermistor. LSU relay PWB. Engine PWB.
• Remedy: LSU thermistor 1. Confirm LSU is displayed by U139 temperature and humidity. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Laser scanner unit and LSU relay PWB (YC3) LSU relay PWB (YC2) and Engine PWB (YC11) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the laser scanner unit.
  LSU relay PWB Replace the LSU relay PWB.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7241
• Description: Broken Developer thermistor wire
  The sensor input sampling is greater than 230.
• Causes: Developer thermistor. Front PWB. Engine PWB.
• Remedy: Developer thermistor 1. Confirm Developing is displayed by U139 temperature and humidity. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Developer unit and Front PWB (YC7) Front PWB (YC2) and Engine PWB (YC8) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the Developer unit.
  Front PWB Replace the front PWB
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7251
• Description: Short-circuited Developer thermistor
  The sensor input sampling is less than 69.
• Causes: Developer thermistor. Front PWB. Engine PWB.
• Remedy: Developer thermistor 1. Confirm Developing is displayed by U139 temperature and humidity. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Developer unit and Front PWB (YC7) Front PWB (YC2) and Engine PWB (YC8) 3. If the wiring is disconnected, shorted or grounded, replace the wiring. 4. Replace the Developer unit.
  Front PWB Replace the front PWB
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.

• Code: 7301
• Description: Toner hopper motor error
  During the toner motor is driven, an event in which a locking was detected for 5 times in 200 ms intervals has occurred in 30 sets.
• Causes: Tonner hopper motor. Screw sensor. Engine PWB.
• Remedy: Tonner hopper motor 1. If the motor won’t rotate, confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Tonner hopper motor and Front PWB (YC5) Front PWB (YC3) and Engine PWB (YC7) 2. If the wiring is disconnected, shorted or grounded, replace the wiring. 3. Replace the tonner hopper motor .
  Screw sensor 1. Check that the sensor is correctly positioned. 2. Confirm that the wiring connector is firmly connected and, if necessary, connect the connector all the way in. Screw sensor and Front PWB (YC5) Front PWB (YC2) and Engine PWB (YC7) 3. Replace the Screw sensor.
  Engine PWB 1. Check the engine software and upgrade to the latest, if necessary. 2. Replace the engine PWB.