DC controller PCB (J320) relay connector thermistor NO Connect the connector. Fixing film unit (thermistor) Check the interval between pin 1 and pin 2 and between pin 3 and pin 4 of the connectosr (4-pin) of the thermistor for electrical continuity. Is it 165;W (open). YES The heater has an open circuit, or the thermal switch is open. Replace the fixing film unit. Main power supply PCB, DC controller PCB Press the Start key. Is the drive voltage of the heater supplied by the connector J8 of the main power supply PCB.

Main heater between J8-1 (FSR1) and J8-5 (FSR COM) Sub heater between J8-3 (FSR2) and J8-5 (FSR COM) YES The heater drive power supply is faulty.