• Code: 310.377
• Description: Fuser On Time Fault. When in Ready or Standby states, the temperature monitor value of the Rear Thermistor did not reach the specified temperature within the specified time after the IH power had turned On.
• Remedy: 1. Turn the power Off and On. 2. Turn the power Off and check the following: • Remove the Fuser Assembly. Inspect the Drawer Connector between the Fuser Assembly and the Main Unit ( DJ600) for broken/bent pins, foreign substances, burns, and etc. • The connection between the DJ600-A2/A3 and the MCU PWB P/J431-10/9 for open circuit, short circuit, and poor contact If no problems are found, replace the following parts in sequence: • Fuser Assembly • MCU PWB

• Code: 310.378
• Description: Heat Belt Rotation Fault. The Belt Speed Sensor output has not changed for 500ms or longer after the Fuser Motor On.
• Remedy: 1. Turn the power Off and On. If the error does not clear, continue to step 2. 2. Turn the power Off and check the following: • Remove the Fuser Assembly. Inspect the Drawer Connector between the Fuser Assembly and the Main Unit ( DJ600) for broken/bent pins, foreign substances, burns, and etc. • The connection between the DJ600-B7/B6/B5 and the MCU PWB P/J431-12/13/14 for open circuit, short circuit, and poor contact If no problems are found, replace the following parts in sequence: • Fuser Assembly • MCU PWB

• Code: 310.379
• Description: Fuser Hot Not Ready Return Time Fault. The time taken to recover from High Temperature Not Ready state has exceeded the specified time.
• Remedy: 1. Turn the power Off and On. If the error does not clear, continue to step 2. 2. Turn the power Off and check the following: • Remove the Fuser Assembly. Inspect the Drawer Connector between the Fuser Assembly and the Main Unit ( DJ600) for broken/bent pins, foreign substances, burns, and etc. • Inspect the connection between the Fuser Assembly DJ600 and the MCU PWB P/ J431 for open circuit, short circuit, and poor contact. If no problems are found, replace the following parts in sequence: • Fuser Assembly • MCU PWB

• Code: 310.380
• Description: P/Roll Latch Motor Fault. When in the P/Roll Contact/Retract operation, the Latch Position Sensor detected a Latch position error of the P/Roll.
• Remedy: • Turn the power Off and check whether the Fuser Assembly is installed properly. • Remove the Fuser Assembly and check the Drawer Connector between the Fuser Assembly and the Main Unit ( DJ600) for broken/bent pins, foreign substances, burns, and etc. • Check whether the MCU PWB connector P/J431 is connected properly.
  Turn the power Off and remove the Rear Upper Cover. Disconnect the connector P592 of the MD PWB and open the Chassis Assembly. Turn the power On and enter Service Diagnostics (Entering Service Diagnostics). Turn On dc330 Component Control [010-009] (P/Roll Latch On) and DC330 [010-010] (P/Roll Latch Off) alternately. Does the Latch Motor rotate? Y↓ N→Is the voltage between the MD PWB P/J520-9 (+) and the GND +24VDC? Y↓ N→Go to +24VDC Power RAP. Turn the power Off, then measure the Latch Motor wire wound resistance. Disconnect the Latch Motor P/J254, then measure the following resistances. • Between Latch Motor P/J254 pin-2 and P/J254 pin-6 • Between Latch Motor P/J254 pin-1 and P/J254 pin-5 Is the resistance approx. 5.7 Ohm for each? (At 25° C / 77° F) Y↓ N→Replace the Fuser Assembly. Measure the resistance between the disconnected connector P/J254-1/2/5/6 and the Frame. Is the resistance infinite for all? Y↓ N→Check the wires of the pins with non-infinite resistance for peeled-off coatings and short circuits due to pinching. If no problems are found, replace the following parts in sequence: • MD PWB • MCU PWB Press the Stop button. Turn On dc330 Component Control [010-009] (P/Roll Latch On) and DC330 [010-202] (P/Roll Latch Sensor), as well as DC330 [010-010] (P/Roll Latch Off) and DC330 [010-202] (P/Roll Latch Sensor) alternately. Does the display change between Low/High? Y↓ N→Is the voltage between the MCU PWB P/J431-4 (+) and the GND +1.2VDC? Y↓ N→Press the Stop button and turn the power Off. Remove the Fuser Assembly and check the connection between the DJ600-A8/A7 and the MCU PWB P/J431-4/5 for open circuit, short circuit, and poor contact. If no problems are found, replace the following parts in sequence: • Fuser Assembly • MCU PWB Press the Stop button and turn the power Off. Remove the Fuser Assembly and check the connection between the DJ600-A6 and the MCU PWB P/J431-6 for open circuit, short circuit, and poor contact. If no problems are found, replace the following parts in sequence: • Fuser Assembly • MCU PWB Turn the power Off and check the Latch Motor Gear for wear or damage. If no problems are found, replace the following parts in sequence: • MCU PWB • MD PWB

• Code: 310.381
• Description: Fuser Assy Illegal Fault. A different type of Fuser Assembly (rapid heating/accumulative heating) was installed.
• Remedy: 1. Turn the power Off and On. If the error does not clear, continue to step 2. 2. Turn the power Off and replace with the correct Fuser Assembly.

• Code: 310.382
• Description: Fuser Thermostat Fault. The Fuser Assembly Thermostat is broken.
• Remedy: • Turn the power Off and remove the Fuser Assembly. Inspect the Drawer Connector between the Fuser Assembly and the Main Unit ( DJ600) for broken/bent pins, foreign substances, burns, and etc. • Check whether the MCU PWB connector P/J431 is connected properly.
  Measure the resistance between P600 pin-A11 and P600 pin-B9. Is the resistance infinite? Y↓ N→Check the following connections for open circuits, short circuits, and poor contacts. • Between DJ600-A1 and MCU PWB P/J431-11 • Between DJ600-B1 and MCU PWB P/J431-18 If no problems are found, replace the MCU PWB. Replace the Fuser Assembly.

• Code: 310.398
• Description: Fuser Fan Fault. The Fuser Fan error was detected.
• Remedy: Rotate the Fuser Fan manually to check for loading.
  Enter dc122 Fault History. Has 041-350 faults (MD PWB F7 Open) occurred? Y↓ N→Enter Service Diagnostics menu (Entering Service Diagnostics). Turn On dc330 Component Control [042-025] (NOHAD FAN Failure Detection). Is the Fuser Fan rotating and does the test return a fuser fan error? Y↓ N→Turn the power Off and check the connection between the Fuser Fan P/J230-4/3/1 and the MD PWB P/J524-10/11/13 for open circuit, short circuit, and poor contact. If no problems are found, replace the following parts in sequence: • Fuser Fan • MD PWB • MCU PWB Replace the Fuser Fan. Press the Stop button and turn the power Off. Check the connection between the Fuser Fan P/J230-2 and the MD PWB P/J524-12 for open circuit, short circuit, and poor contact. If no problems are found, replace the following parts in sequence: • MD PWB • MCU PWB Go to the 341.350 RAP.

• Code: 310.420
• Description: Fuser Assembly Near Life Warning The Fuser Assembly is near the end of its life span.
• Remedy: Replace the Fuser Assembly with a new one and clear dc135 CRU/HFSI Read & Reset [954-850]. If the problem persists, replace the MCU PWB.