Daikin FTX25JVEA9 Service Manual page 314

Si18-201
3.4.3 Electronic Expansion Valve Check
Check No.3 Conduct the followings to check the electronic expansion valve (EV).
1. Check to see if the EV connector is correctly inserted in the PCB. Compare the EV unit and
2. Turn the power off and back on again, and check to see if all the EVs generate latching
3. If any of the EVs does not generate latching noise in the above step 2, disconnect that
4. If no EV generates latching sound in the above step 2, the outdoor unit PCB is faulty.
5. If the conductivity is confirmed in the above step 2, mount a good coil (which generated
Note: Please note that the latching sound varies depending on the valve type.
3.4.4 Fan Motor Position Signal Check
Check No.4
Measurement method
1. Turn the power supply on.
2. Check the voltage of U-,V-,W-Phase of the above upper and lower fans with fan rotating.
3. The waveform measured will be as shown below.
4. It is OK if , as shown above 3, approximately 5V voltage is turned on and off.
Service Diagnosis
the connector number.
sound.
connector and check the conductivity using a tester.
Check the conductivity between pins 1, 3 and 6, and between pins 2, 4 and 5. If there is no
conductivity between the pins, the EV coil is faulty.
latching sound) in the EV unit that did not generate latching sound, and check to see if that
EV generates latching sound.
∗
If latching sound is generated, the outdoor unit PCB is faulty.
∗
If latching sound is not generated, the EV unit is faulty.
GND
PCB2
S514 (B)
(A) (A)
Q504
U
Harness 6P Harness 5P
6P Connector 5P Connector
1 2 3 4 5 6 1 2 3 4 5

5 – 2

5 – 4

Check Check

6 – 1

6 – 3
S504 S501 S506
(A) (A) (A) (A)
Q503 Q502 Q507 Q506 Q505
V W U V W
(Q0003)
+5V
(Q0004)
Troubleshooting - Outdoor Unit Related

5 – 1

5 – 2


5 – 3

5 – 4
Locations for measurement
(Upper/Lower fans + U-,V-,W-
Phase)
Multiple-meter, + side (A)
- side (B)
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