This error occurs when the heating temperature in the fuser unit is not reached during warm up or operation time:
- When the fusing temperature is lower than 150C° after 55sec from the start of warming up.
- When the warming up complete temperature is not reached in 30sec from reaching 150C°.
- When the fusing temperature is lower than 100C° after 20sec from ready start.
- When the fusing temperature is lower than 145C° when printing.”
• Heater lamp disconnection or burnt out.
• Thermistor defective or dirty.
• Low power voltage in the mains supply.
• Thermal fuse out or thermostat cutout.
How To Fix Error Code H4-00 ?
1st Method : “Reset Code”
You simply reset the error code by :
- OFF and then ON the copier again
- PRESSE #, interupt, C, interupt, then input 14 then start.
- Unit should power off and the restart.
- Use SIM 5-02 to check the heater lamp blinking operation.
- When the lamp blinks normally.
- Check the thermistor and its harness.
- Check the thermistor input circuit on the control PWB. When the lamp does not light up.
- Check for disconnection of the heater lamp and the thermostat.
- Check the interlock switch.
- Check the power PWB and the lamp control circuit on the MCU PWB. Use SIM 14 to clear the self diagnostic display.
- Measure power using voltmeter and wait till it stabilizes.