3-176 Phaser 7400 Color Printer Service Manual[CM][YK] Toner Supply FailureThe Low Toner Sensor indicates a supply failure at the indicated Imaging Unit.Applicable Status Codes:Code 941: Toner supply failure with Cyan or Magenta Toner.Code 942: Toner supply failure with Yellow or Black Toner.Initial Actions:■ Cycle the printer's power.■ If the problem persists follow the procedure below.Troubleshooting Reference TableApplicable Parts Wiring and Plug/Jack References■ Toner Cartridges, PL1.1.24■ Imaging Unit, PL1.1.23■ Toner Motors, PL5.1.22■ Imaging Unit Sensor Board, PL5.1.21■ Print Engine Map 5 (page 10-8)■ Print Engine Map 8 (page 10-11)■ Print Engine Motor Driver Board (2/6) (page 10-32)■ Print Engine Imaging Unit Sensor Board (page 10-41)Troubleshooting Procedure TableStep Actions and Questions Yes No1 Check the following for evidence of fault ordamage:■ Toner Cartridge■ Imaging Unit Agitator Bar■ Low Toner SensorsIs there any damage, debris or blockage?Replace anydamaged parts.Go to Step 2.2 Test the affected Toner Motor.1. Remove the CM or YK Toner Cartridges.2. Run the appropriate Service DiagnosticsToner Supply Motor test.Does the motor rotate?Go to Step 3. Replace the motor(page 8-104). If theerror persists,replace the MotorDriver Board(page 8-141).3 Does the plunger that engages theAgitation Bar move in and out while theToner Motor rotates?Go to Step 4. Replace the TonerSupply Camshafts(page 8-144).4 Test the affected Low Toner Sensors.1. Remove the CM or YK Imaging Units.2. Run the appropriate Service DiagnosticsToner Cart Sensor test.Do the sensors function correctly?Replace the EngineControl Board(page 8-112)Replace theImaging UnitSensor Board(page 8-142).
