Try to replace Q3 with the domestic bidirectional thyristor model 3CTS10.

by bwgh31zv on 2011-08-15 18:17:16

**Rongshida Automatic Washing Machine - Not Working**

**Fault Phenomenon:** After power-on, the indicator light is on, but the motor does not rotate.

**Analysis and Maintenance:** After disconnecting the power, both windings of the motor were measured to be normal. A wire was used to short-circuit the two terminals of the water level pressure switch, then the power was turned on. The external crystal oscillator connected to pin 41 and pin 1 of the CPU was found to be normal. Control signals were also detected at pins 12, 13, 14, 15, and 17 of the CPU. The -25V voltage at pin 8 of the control IC (IR7403) was normal. During the washing process, a control voltage output was also detected at pin 16. After removing the bidirectional thyristor T1 for measurement, it was found to be damaged.

**Solution:** Replace the bidirectional thyristor T1.

**Emergency Measures:** Since the original model (BCR16AM) thyristor could not be found, a domestically produced bidirectional thyristor with model number 3CTS10 was tried as a replacement, successfully eliminating the fault.

**Source of Information:** Beijing Rongshida Washing Machine Repair Center

http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3447654