Source: Beijing Haier Washing Machine Repair Center http://blog.163.com/haier_xiyiji1/.
Fault Phenomenon: After the power is connected, the indicator light does not illuminate.
Testing and Judgment: First, check that the power cord, fuse, and power switch are all normal. Use a multimeter to measure the voltage between the two yellow and orange single-core sockets on the power input terminal of the program controller. The actual measurement shows 220V voltage which is normal, indicating that the circuit from the power plug to the power input terminal of the program controller is normal. The fault may be in the program controller.
Under powered state, at the Beijing Haier Washing Machine Repair Center, press each button on the program controller respectively, and use a multimeter to measure no voltage between the two leads of the corresponding indicator light (it should normally be around 2V DC voltage), thus judging that there is either a short circuit or an open circuit inside the program controller.
Repair Method: After replacing the program controller with the same model, the fault was eliminated.
Repair Experience: If the voltage between the leads of the corresponding indicator light is measured to be around 2V, it can be judged that the LED itself is damaged. Just replace it with the same type of diode to eliminate the fault.