Common faults in copier thermistors

The copier is an indispensable device in our office. For copiers, the role of the copier's thermistor is crucial. Once a failure occurs, it will have various effects. So what are the common faults?

According to the preheating time of the copier, it can be divided into three cases. First, it is in the warm-up state for a long time, and it is not converted to the copy state, and the fixing lamp is not lit. The fault is mostly that the fuser lamp is damaged or there is no power supply. Check the supply voltage and the fuser heater first. In a power supply circuit, the triac is often damaged. To judge the quality of the thyristor, you can directly measure the voltage between the two anodes under working conditions, or measure the interelectrode resistance with a multimeter ohmmeter. The method is: the multimeter is set to the R×1Ω low gear. When normal, the resistance between the two-way thyristor anode and the gate should be very low, and the other pole resistances should be approximately infinite, otherwise the two-way controllable is damaged.

The second is to display the fault code within a short time after power on. A fixing fault self-test code is set in the middle of each model copier, and the temperature change time is used to determine the range of the fault during the warm-up process. In addition, after the copier is powered on, the thermistor does not sense the change in temperature within the predetermined warm-up time, and it is determined that there is a problem with the heater lamp, the thermistor, the temperature fuse, and the connecting wire.