Service Manual

SiUS091133 Check
Service Diagnosis 144
5.4 Power Supply Waveforms Check
Check No.11 Measure the power supply waveform between No. 1 and No. 2 on the terminal board, and check
the waveform disturbance.
 Check to see if the power supply waveform is a sine wave. (Fig.1)
 Check to see if there is waveform disturbance near the zero cross. (sections circled in Fig.2)
5.5 Electronic Expansion Valve Check
Check No.12 Conduct the followings to check the electronic expansion valve (EV).
1. Check to see 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 and
check the continuity using a tester.
4. Check the continuity between the pins 1 - 6, 2 - 6, 3 - 6, and 4 - 6. If there is no continuity
between the pins, the EV coil is faulty.
5. If the continuity is confirmed in step 3, the outdoor unit PCB is faulty.
Note: Please note that the latching sound varies depending on the valve type.
Fig.1 Fig.2
Harness 5P
S20
6P Connector
(5)
Check
6-1
6-2
6-3
6-4
1 2 3 4 5 6
(R14212)