600B4602

Error 600 OKI B4602: Fuser Overheat Failure

The OKI B4602 error 600 is a thermal safety alarm triggered by fuser unit overheating. This state locks the printer to prevent hardware melting or damage. It is essential to follow a strict cooling-off period and ensure adequate ventilation for the machine.

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Common causes

  • 1Extreme print volume without resting.
  • 2Blocked internal cooling fans.
  • 3Faulty temperature sensor (thermistor).
  • 4High ambient temperatures in poorly ventilated areas.

Solutions

Diagnóstico rápido

Error 600 is a direct overheat warning. If the printer has been running heavy print jobs, it simply needs a cooling break. If this persists at startup, the thermal sensor is likely reporting faulty data.

Solución paso a paso

  1. Power Off: Unplug and allow 45 minutes for internal heat to dissipate.
  2. Clear Vents: Ensure side grids are free of dust buildup.
  3. Environment: Ensure the printer is not in an enclosed shelf.
  4. Restart: The printer self-check should clear the alert if the thermal state is normal.

Prevención y mantenimiento

Ensure at least 6 inches (15cm) of space around the printer. Regular cleaning of internal fans prevents heat accumulation.

Cuándo llamar a un técnico

If the error 600 reappears instantly after a cold start (after a long cooling period), the thermistor is likely shorted and requires professional replacement.

Ficha técnica del equipo

Steps to follow

  1. 1

    Cool Down

    Power off and unplug for 45 minutes to let internal heat dissipate.

  2. 2

    Output Inspection

    Verify the rear paper path is clear of any debris.

  3. 3

    Clean Vents

    Use compressed air to clear accumulated dust from side ventilation grids.

  4. 4

    Restart

    Power on in a well-ventilated room to verify if the code clears.

Frequently asked questions

Error 600 is a safety thermal alarm indicating the fuser has exceeded safe operating temperatures.

Yes, overheating can melt internal parts. Always wait for a full cooldown before turning it back on.

Poor quality toner may increase friction, which causes the fuser to work harder and run hotter.

Ensure proper airflow around the printer and avoid back-to-back high-volume print tasks.