Daikin Inverter Wall Mounted Single Split FTXB12AXVJU

Warning: This procedure requires trained personnel with PPE!

Enter the power supply waveform measurement between No. 1(Live) and No. 2(Neutral) on the terminal board

Upload the oscilloscope screenshot of the waveform

Is the power supply waveform a sine wave (Refer to Fig. 1)?

Is there waveform disturbance near the zero cross (sections circled in Fig. 2)?

Sign off on the power supply waveforms check

Set operation off and power off. Disconnect the connector S71.

Control voltage between the pins 3 & 4

Rotation command voltage between the pins 2 & 4

Keep operation off and power off. Connect the connector S71.

Pulses output at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

If NG in step 2 : Defective PCB and replace the outdoor unit PCB.

If NG in step 4 : Defective Hall IC and replace the outdoor fan motor.

EXV connector correctly connected to PCB

EXV generates a latching sound when power is turned off and on

If EXV does not generate a latching sound, proceed to next step

Continuity confirmed when connector is disconnected and checked with a multimeter

Check the continuity between pins

If there is no continuity between the pins, EXV coil is faulty

Continuity confirmed between the pins

If the continuity is confirmed, outdoor PCB is faulty

Sign off on the Electronic Expansion Valve Check

Warning: Ensure the voltage between (+) and (-) of the diode bridge (DB1) is approximately 0 V before proceeding

Enter the resistance between the pins of the DB1

Is the resistance ∞ or less than 1 kW?

If the resistance is ∞ or less than 1 kW, a short circuit occurs on the main circuit.

Sign off on the main circuit short check

Warning: Ensure the voltage between the terminal of Power transistor (+) and (-) is approx. 0 volt before proceeding

Voltage between the terminal of Power transistor (+) and (-) is approx. 0 volt

Disconnect the compressor harness connector from the outdoor unit PCB. To disengage the connector, press the protrusion on the connector.

Measure resistance between power transistor (+) and (-) and the U terminal of the compressor connector

Measure resistance between power transistor (+) and (-) and the V terminal of the compressor connector

Measure resistance between power transistor (+) and (-) and the W terminal of the compressor connector

Evaluate the measurement results for a pass/fail judgment

Sign off on the power transistor check