• Code: 923
• Description: Fuser Error
  Fuser is too hot during printing or when printer is idle.
• Remedy: 1 Fuser Lamp (Incorrect Lamp/925 Service Error) Install the correct voltage and wattage lamp or fuser assembly. 2 Fuser Lamp Remove the controller board. Run the Diagnostic Print Test and observe the lamp through the left side frame. If the lamp doesn’t come on, unplug the printer and check the continuity between the two pins on the fuser lamp cable going to the fuser assembly. If you do not measure continuity, remove the fuser assembly and check the continuity of the lamp. If incorrect, replace the lamp. If correct, replace the fuser cover assembly. 3 LVPS LVPS to Fuser Auto Docking Connector Fuser AC Cable Turn the printer off. Remove the fuser assembly. Turn the printer power on. Measure across the AC fuser cable pins for line voltage with the cable connected. If incorrect, turn the printer off and disconnect the power cord. Check the continuity of the LVPS to fuser AC cable. If incorrect, replace the cable. If correct, replace the LVPS. 4 Fuser Top Cover Assembly (Thermal Fuse/Thermistor Assembly) Disconnect the thermistor cable from the fuser board at J2. The resistance is as follows: HOT - J2-1 - J2-2 = 2.5K ohms COLD = 150K ohms to 260K ohms

• Code: 924
• Description: Fuser Error
  An open circuit has been detected in the Fuser Thermistor Circuit.nter is idle.
• Remedy: 1 Fuser Lamp (Incorrect Lamp/925 Service Error) Install the correct voltage and wattage lamp or fuser assembly. 2 Fuser Lamp Remove the controller board. Run the Diagnostic Print Test and observe the lamp through the left side frame. If the lamp doesn’t come on, unplug the printer and check the continuity between the two pins on the fuser lamp cable going to the fuser assembly. If you do not measure continuity, remove the fuser assembly and check the continuity of the lamp. If incorrect, replace the lamp. If correct, replace the fuser cover assembly. 3 LVPS LVPS to Fuser Auto Docking Connector Fuser AC Cable Turn the printer off. Remove the fuser assembly. Turn the printer power on. Measure across the AC fuser cable pins for line voltage with the cable connected. If incorrect, turn the printer off and disconnect the power cord. Check the continuity of the LVPS to fuser AC cable. If incorrect, replace the cable. If correct, replace the LVPS. 4 Fuser Top Cover Assembly (Thermal Fuse/Thermistor Assembly) Disconnect the thermistor cable from the fuser board at J2. The resistance is as follows: HOT - J2-1 - J2-2 = 2.5K ohms COLD = 150K ohms to 260K ohms

• Code: 925
• Description: Fuser Error
  Wrong fuser lamp installed.
• Remedy: Check the fuser lamp for the correct type of lamp that should be installed. If the correct lamp has been installed and you still have a 925 error, the following may be the cause: 1. The fuser may have reached standby temperature too quickly. 2. Check too make sure the correct hot roll has been installed. 3. Check the line voltage to make sure it is not above the maximum rating for the printer.

• Code: 927
• Description: Fan Stalled
  Indicates a printer fan stalled.
• Remedy: 1 Fan Assembly Check the fan for proper installation and for excessive noise. If incorrect, replace the fan and cable assembly. 2 Engine Board Check to make sure the auxiliary fan cable is seated on connector J7 on the engine board. If correct, check for +24 V dc on J7-1 on the engine board. If incorrect, replace the engine board. If correct, replace the fan assembly. Note: When the printer is in warmup the voltage at J7-1 measures approximately +12 V dc. When the printer is running, the voltage measures approximately +24 V dc.

• Code: 928
• Description: Erase Lamps
  Indicates that the engine has detected that either the erase lamp assembly is missing or disconnected.
• Remedy: 1 Cable, Front Harness Check the connection of the front harness to connector J10 on the engine board for correct installation. If incorrect, repair as necessary. Check the front harness to erase lamp assembly for correct installation. If incorrect, repair as necessary. 2 Engine Board Remove the controller board and toner cartridge from the machine. Ground pin J10-15. The erase lamps turn on. The lamps can be observed through the front of the machine with the cover open and print cartridge removed. If the lamps do not turn on, measure the voltage on J10-14. The voltage reads approximately +24 V dc. If incorrect, replace the engine board. If correct, check the voltage at J10-15. The voltage reads between +15 V dc to +20 V dc. If incorrect, check the continuity of the erase lamp lines in the main harness. If incorrect, replace the cable harness. If correct, replace the erase lamp assembly.

• Code: 929
• Description: Toner Sensor
  The toner sensor is not operating properly, the developer drive assembly is not operating properly or the print cartridge is defective.
• Remedy: 1 Developer Drive Assembly Incorrect operation of the developer drive assembly can cause the printer to display a 929 error code (Toner Sensor). Check the developer drive assembly for correct installation, any sign of worn, loose or broken parts. 2 Front Harness Cable Check the toner sensor portion of the front harness cable to make sure it is properly seated into the toner sensor. If correct at both the sensor and engine board (J10), check the continuity of the cable. If incorrect, replace the cable. 3 Toner Sensor The toner sensor cable is part of the front harness and part of connector J10 on the engine board. Check the voltage at J1-011. It reads approximately +5 V dc. If incorrect, replace the engine board. If correct, check the voltage at J10-12. It reads approximately +5 V dc with the controller board removed from the printer. If incorrect, replace the engine board. If correct, replace the toner sensor assembly. A bad ground connection between J10-13 on the engine board and pin 3 on the toner sensor results in a 929 service error.

• Code: 930
• Description: Printhead Error
  The wrong printhead is installed.
• Remedy: Replace with the correct printhead.

• Code: 931
• Description: Printhead Error
  These errors represent a problem with the printhead.
• Remedy: 1 Error Code 931 No first HYSNC Signal Error Code 932 Lost HYSNC These errors usually indicate a failure in the HYSNC signal to the printhead. Check the continuity of the cables connected to J3 and J8 on the engine board. If incorrect, replace the defective cable. The voltage at J8-4 measures approximately +5 V dc. If incorrect, replace the engine board. The voltage at J3-7 measures approximately +24 V dc. If incorrect, replace the engine board. If correct, replace the printhead assembly. 2 Error Code 934 Mirror Motor Lost Lock Error Code 935 Mirror Motor unable to reach operating speed These error codes indicate a problem with the mirror motor circuit in the printhead assembly or the mirror motor cable to the engine board cable or engine board assembly. Check the continuity of the mirror motor cable connected to J3 on the engine board. If incorrect, replace the cable. The voltage at J3-7 measures approximately +24 V dc. If incorrect, replace the engine board. If correct, replace the FRUs in the following order: engine board