Samsung repair technology information; washing machine operation failure, indicator light does not light up 65

**Samsung Repair Technology Information; Washing Machine Operation Failure, Indicator Light Not On**

**Fault Phenomenon:** After connecting the power supply, the washing machine fails to operate, and the indicator light does not turn on.

**Inspection and Judgment:** Based on a principle analysis, the machine's operating voltage is transformed by a transformer, then rectified, filtered, and stabilized into low-voltage DC. This transformer is separate and connected to the load drive board via a wire plug. Since the indicator light does not turn on, the possible causes of the fault are analyzed as follows: poor power supply voltage, issues with the power circuit, or problems with the circuit board. The washing machine's specified minimum operating voltage is 85% of the rated voltage (i.e., 187V). When the voltage is too low, the transformer's output voltage also decreases correspondingly, resulting in insufficient output power from the transformer, which prevents the microprocessor IC1 from functioning normally. The measured mains voltage was 215V AC (basically normal), and no abnormalities were found in the computer circuit board. However, during the inspection of components such as the power switch, power transformer, and fuse, it was discovered that the fuse had blown.

**Repair Method:** After replacing the fuse with one of the same specification, the machine was powered on for testing, and the fault was resolved.

**Source of Information:** http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3451922.