Power Supply Waveforms Check; Electronic Expansion Valve Check - Daikin FTX20K(2)V1B Service Manual

Check
5.3

Power Supply Waveforms Check

Measure the power supply waveform between No. 1 and No. 2 on the terminal board, and check
Check No.11
the 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).
Fig.1
5.4

Electronic Expansion Valve Check

Conduct the followings to check the electronic expansion valve (EV).
Check No.12
1. Check if the EV connector is correctly connected to the PCB.
2. Turn the power off and on again, and check 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
4. Check the continuity between the pins 1 - 6, 2 - 6, 3 - 6, and 4 - 6 (between the pins 1 - 5, 2 -
5. If the continuity is confirmed in step 3, the outdoor unit PCB (main PCB) is faulty.
81
and check the continuity using a multimeter.
5, 3 - 5, 4 - 5 for the 5P connector models). If there is no continuity between the pins, the EV
coil is faulty.
Harness 5P
(5)
S20
6P Connector
1 2 3 4 5 6
Fig.2
(R1736)
1 - 6
S20
2 - 6
Check
3 - 6
4 - 6
(R16386)
Harness 5P
Check
5P Connector
1 2 3 4 5
Service Diagnosis
SiBE041525F
(R1444)
1 - 5
2 - 5
3 - 5
4 - 5
(R20506)