Daikin Indoor Unit Wall Mounted Multi-Split Type Air Conditioner FTXR09WVJUS9

Warning: This procedure requires trained personnel with PPE!

Disconnect the connector of thermistor ASSY from the PCB to measure the resistance between the pins using multimeter.

Enter the measured resistance value of the thermistor

Does the measured resistance value match the listed value?

To check the thermistor soldered on a PCB, disconnect the PCB from other PCB/parts, and measure the resistance between the both ends of soldered thermistor.

Enter the measured resistance value of the soldered thermistor

Does the measured resistance value of the soldered thermistor match the listed value?

Did all thermistors pass the resistance check?

Sign off on the thermistor resistance check

1. Check the connection of connector.

2. Check motor power supply voltage output (pins 4 - 7).

3. Check motor control voltage (pins 4 - 3).

4. Check rotation command voltage output (pins 4 - 2).

5. Check rotation pulse input (pins 4 - 1).

2. With the fan motor connector disconnected, measure the resistance between each pin, then make sure that the resistance is more than the value mentioned in the following table.

Warning: This check requires trained personnel with PPE!

Enter the power supply waveform measurement between No. 1 and No. 2 on the terminal strip

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

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

Upload a photo of the measured waveform

Sign off on the power supply waveform check

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 without touching each other?

Activate the power transistor test operation from the outdoor unit.

Forced cooling operation ON/OFF switch pressed for 5 seconds?

Diagnose according to 6 LEDs lighting status.

Warning: Ensure the voltage between (+) and (-) of the power module is about 0 V before proceeding

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

Compressor harness connector successfully disconnected?

Measure resistance between the (+) or (-) terminal of the power module and the U, V, or W terminal of the compressor with a multimeter.

Enter the resistance measurement

Evaluate the measurement results

Sign off on the power module check