Daikin Outdoor Unit Wall Mounted Type Air Conditioner RX25K2V1B

Set operation off and power off. Disconnect the connector S70 or 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 S70 or S71.

Rotation pulses at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

Outdoor fan motor functioning properly?

Warning: This procedure requires trained personnel with PPE!

Install an inverter analyzer instead of a compressor.

Charged voltage of the built-in smoothing electrolytic capacitor dropped to 10 VDC or below?

Terminals removed from the compressor?

Terminals connected to the terminals of the inverter analyzer?

Warning: Be careful not to let the terminals (U,V,W) touch each other. Otherwise, high voltage is applied.

Power transistor test operation activated from the indoor unit?

Diagnose method (Diagnose according to 6 LEDs lighting status.)

Warning: This check requires trained personnel with PPE!

Measure the power supply waveform between No. 1 and No. 2 on the terminal board

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

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

Upload a photo of the measured waveform

Sign off on the power supply waveforms check

Warning: Ensure the voltage between (+) and (–) of the diode bridge (DB1) is about 0 V before checking.

Enter the voltage between (+) and (–) of the diode bridge (DB1)

Measure the resistance between the pins of the DB1 referring to the table below.

Enter the resistance between the pins of the DB1

Is the resistance ∞ or less than 1 kΩ?

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

Sign off on the main circuit short check

EV connector correctly connected to the PCB

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

Continuity confirmed when connector is disconnected and checked with a multimeter

Check the continuity between the pins

EV coil is not faulty if there is continuity between the pins

Outdoor unit PCB (main PCB) is not faulty if continuity is confirmed

Sign off on the electronic expansion valve check