The malfunction light is flashing eo.

Changhong Repair Case: The compressor of KFR-30GW air conditioner does not start, and the fault light is flashing.

Analysis and Testing: The room temperature sensor measures well. The measurement of the electric control board matches the calibration. The filter capacitor (470uF/10V) measures well. When measuring the resistance R28 at the output end of pin 26 of the main chip D1, it is already open-circuited.

Repair Method: Replace R28 with a 1kΩ resistor, and the fault is eliminated.

Warm Tips: CT current protection is used for overcurrent protection of the air conditioner compressor. The sensed current in CT1 of this circuit, after being rectified by VC2, filtered by R36 and C31, then added to pin 26 of the MCU main chip D1 via R28. If the voltage is higher than 3.2V, the MCU determines that the working current of the air conditioner exceeds the set value, and the compressor will immediately stop working.

Source: Beijing Changhong Air Conditioner Repair Center http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3766321.