As a result, the relay inside the power supply switch will be supplied with power, thepower switch will be turned off, and the AC power supply will be cut off (error auto poweroff).Figure 6-1103. Fixing Heater Error Activation Detection CircuitThe gate array generates the fixing heater ON signal (SSR ON), and receives thefixing heater ON detection signal (SSR ACTIVE). An error is identified if the fixing heateris on in the absence of the fixing heater ON signal.At this time, the gate array communicates an error in the activation of the fixingheater to the master CPU and, at the same time, generates the power switch OFF signal.In addition, the thermistor used to monitor the surface temperature of the fixing rollergenerates the error signal (FUSER TEMP ERROR) to the gate array. The gate array willalso turn off the power switch in response to an abnormal increase in the surfacetemperature of the fixing roller.When the power supply switch OFF signal is generated, the relay inside the powerswitch is powered to turn off the power switch and the AC power supply.If the fixing sub thermistor (TH2) detects an abnormal increase in temperature (230±10°C), the DC controller PCB indicates ‘E001’, and turns off the AC power supply.The machine checks the fixing sub thermistor for a broken line, and indicates ‘E000’for about 5 sec if it finds an open circuit and cuts off the AC power supply.LampregulatorMasterCPUDC controller PCBGatearrayCVRACTIVELA1Power switch OFFError+12VCVR ONCOPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 6 FIXING SYSTEM6-16
