故障现象：开机后机器处于自我保护状态，自诊面板显示显影水位偏低。分析排除：拆机后仔细观察机器内部状况。主控制板上两电阻R37‘R38发黑烧毁，后级双向可控硅经表测量未有损坏，对照板上类似电路参数更换电阻；机内循环管道多处呈黑色，显影液入口处管子呈深褐色，彻底清 Symptom: After the machine is turned on, the machine is in a self-protected state. The self-diagnosis panel shows that the water level is low. Analysis and Exclusion: After dismantling, carefully observe the internal conditions of the machine. The two resistors R37’R38 on the main control board are black burned. The rear bidirectional thyristor has not been damaged by the meter, and the resistance is replaced with the circuit parameters on the control board; the internal circulation pipes are black in many places and the tube at the inlet of the developer is Dark brown, completely clear