**Sanyo Washing Machine: Continuous Water Inflow (Bi-directional Thyristor Breakdown)**
**Fault Phenomenon:** The washing machine can automatically fill with water, but after the water reaches the set water level, it continues to fill without stopping, and the agitator does not rotate.
**Analysis and Maintenance:** Based on the fault phenomenon, the washing machine has not yet entered the washing state but remains in the water-filling state. The causes of this fault include: a malfunction in the water inlet control circuit, a faulty water level pressure switch, or a damaged electromagnetic water inlet valve. First, check the electromagnetic water inlet valve. After turning off the power, the water inflow stops, indicating that the electromagnetic water inlet valve is functioning properly. Next, check the pressure switch. After replacing it with a same-model switch, the water inflow still does not stop, leading to the conclusion that there is a problem with the control circuit. From the analysis of the water inlet control circuit principle, the main reasons for continuous water inflow are often damage to the microprocessor MN15828 or breakdown of the bi-directional thyristor TR6. After testing, the MN15828 is found to be normal, but upon inspection, it is discovered that TR6 has broken down.
**Handling Measures:** Replace the bi-directional thyristor with the same model, and the fault is resolved.
**Source of Information:** Beijing Sanyo Washing Machine Repair Center
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