Check SiUS091601E103 Service Diagnosis5.3 Power Supply Waveforms CheckCheck No.11 Measure the power supply waveform between No. 1 and No. 2 on the terminal board, and checkthe waveform disturbance. Check if the power supply waveform is a sine wave (Fig.1). Check if there is waveform disturbance near the zero-cross (sections circled in Fig.2).5.4 Electronic Expansion Valve CheckCheck No.12 Conduct the followings to check the electronic expansion valve (EV).1. Check if the EV connector is correctly connected to the PCB.2. Turn the power off and on again, and check to see if the EV generates a latching sound.3. If the EV does not generate a latching sound in the above step 2, disconnect the connector andcheck the continuity using a multimeter.4. Check the continuity between the pins 1 - 6, 2 - 6, 3 - 6, and 4 - 6 (between the pins 1 - 5, 2 - 5,3 - 5, 4 - 5 for the 5P connector models). If there is no continuity between the pins, the EV coil isfaulty.5. If the continuity is confirmed in step 3, the outdoor unit PCB (main PCB) is faulty.Fig.1 Fig.2Harness 5P5P Connector CheckS201 - 52 - 53 - 54 - 51 2 3 4 5(R20506)Harness 5P6P Connector(5)CheckS201 - 62 - 63 - 64 - 61 2 3 4 5 6(R16386)
