Source: Beijing Bosch Washing Machine Repair Center http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3446026. Fault Analysis: The main cause of this fault is either the malfunction of the computer board control or an issue with the drainage system. Fault Inspection: First, it should be determined whether the fault lies in the computer control board or the solenoid valve. Using a multimeter on the DC setting to measure the voltage between the two ends of the solenoid coil's lead wires (brown wire is negative, purple wire is positive), a 200V DC voltage was detected. This indicates that the drive circuit on the computer control board has sent out voltage to the solenoid, so the fault should be in the solenoid valve. The resistance of the pull-in coil measured around 110Ω, which is normal. After disassembling the interlocked micro-switch on the solenoid valve and measuring the coil resistance, it was found to be approximately 3200Ω, also normal. When checking the fuse resistor, it was discovered that the resistor had become open-circuited, causing the aforementioned fault. After replacing the fuse resistor, the machine was tested and the washing machine operated normally, resolving the fault. Bosch washing machine drainage failure, all other functions normal.