Fuser failure detection The DC controller determines if the fuser functions properly. The DC controller determines a fuser failure, interrupts power supply to the fuser heater and notifies the formatter of a failure state when it encounters the following conditions: ● Abnormally high temperature 1 The main thermistor detects 240°C (464°F) or higher for a specified period. ● Abnormally high temperature 2 The sub thermistor 1 detects 230°C (446°F) or higher for a specified period during WAIT period. The sub thermistor 1 detects 230°C (446°F) or higher for a specified period before INTR starts. The sub thermistor 1 detects 300°C (572°F) or higher for a specified period.
● Abnormally high temperature 3 Either one of the sub thermistor 2 or sub thermistor 3 detects 230°C (446°F) or higher for a specified period during WAIT period. Either one of the sub thermistor 2 or sub thermistor 3 detects 230°C (446°F) or higher for a specified period before INTR starts. Either one of the sub thermistor 2 or sub thermistor 3 detects 300°C (572°F) or higher for a specified period. ● Abnormally low temperature 1 The main thermistor detects 60°C (140°F) or lower for a specified period during WAIT period. The main thermistor detects 70°C (158°F) or lower for a specified period during heater temperature control of INTR period.
The main thermistor detects the targeted temperature minus 40°C (104°F) or lower for a specified period during heater temperature control or pressure roller cleaning of PRINT period. The main thermistor detects 80°C (176°F) or lower for a specified period during heater temperature control or pressure roller cleaning of PRINT period. ● Abnormally low temperature 2 The sub thermistor 1 detects 60°C (140°F) or lower for a specified period during WAIT period. ● Abnormally low temperature 3 Either one of the sub thermistor 2 or sub thermistor 3 detects 60°C (140°F) or lower for a specified period during WAIT period.
● Abnormal temperature rise The main thermistor detects the targeted temperature minus 10°C (50°F) or lower for a specified period during heater temperature control of INTR period. ● Drive circuit failure 18 Chapter 1 Theory of operation ENWW