Abnormal temperature display (no display/excessive deviation)?

Fault phenomenon: The temperature controller has no temperature display, or the displayed temperature deviates too much from the actual temperature, making it impossible to refer to.

Core cause: Damage or poor contact of temperature sensor; Signal line is broken or loose; Control board (computer board) malfunction.

Solution: Use a multimeter to check the resistance of the sensor (PT100 is about 100-110 Ω at room temperature). If it is abnormal, replace it; Tighten the wiring terminals and replace damaged signal wires; If all of the above are normal, it may be a control board malfunction and needs to be replaced or sent for repair.