**Troubleshooting Method:** Replace R25, test the machine, and the fault is resolved. Beijing Little Swan Washing Machine Repair Center.
---
**Inspection and Judgment:** First, check the motor and its wiring, and no abnormal phenomena are found. It is estimated that the problem may lie in the load drive circuit. The microprocessor IC1 (CPU) of this machine controls the peripheral electrical components on the control board through pins 46-49 and 51, 52, which are driven by integrated circuit IC2. Since pin 7 of IC2 is the common emitter for six internal transistors, an additional transistor can be externally connected to perform overall control through pin 45 of the IC. In this way, only when pin 45 of IC1 allows output will each control output port conduct, and the +5V power supply enters IC2 via the gate of the bidirectional thyristor and current-limiting resistor, then flows to ground through the common emitter and transistor Q10. There is a certain voltage drop across the thyristor, so the thyristor conducts, enabling the external electrical components to operate. Two thyristors controlling the motor are paralleled with RC absorption circuits to prevent overvoltage from the power grid from damaging the thyristors and electrical components. When there is an instantaneous overvoltage, the capacitor charges, and since the charging time of the capacitor is much longer than the duration of the overvoltage, the capacitor protects the electrical components. The charge on the capacitor can be discharged through resistors R24 and R25. Based on the above analysis, gradually check related components such as TR2, TR4, C7, C9, R25, C16, R24, C13, R21, R29, R37, Q10, C12, C5, etc., and it is found that R25 has deteriorated and failed.
---
**Fault Phenomenon:** After powering on, the washing machine indicator light turns on, but the motor does not rotate.
---
**Xiao Tian'e XQB40-868FC (G) Washing Machine Motor Does Not Rotate**
---
**Beijing Xiao Tian'e Washing Machine Repair Center - Edited Materials**