Daikin Indoor Unit Wall Mounted Type FTX15NMVJUA

Warning: This procedure requires trained personnel with PPE!

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

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 waveform check

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

Voltage between (+) and (–) of the power module is about 0 V

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

Compressor harness connector disconnected

Measure resistance between the terminals of the power module and the terminals of the compressor with a multimeter.

Enter the resistance measurement

Evaluate the measurement results

Sign off on the power module check

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

Control voltage between the pins 4 - 3

Rotation command voltage between the pins 4 - 2

Keep operation off and power off. Connect the connector S70 or S71.

4 rotation pulses (0 ~ 15 VDC) at the pins 4 - 1 when the fan motor is rotated 1 turn by hand

Outdoor fan motor functioning properly?

Warning: Disconnect the thermistor from the PCB before measuring

Enter the resistance value of the thermistor

Does the measured resistance match the listed value?

Upload a photo of the replaced thermistor

Sign off on the thermistor resistance check

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

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

Is the voltage approximately 0V?

If voltage is not approximately 0V, stop the procedure and report the issue

Enter the resistance between the pins of the DB1

Compare the resistance with the table

Does the resistance indicate a short circuit?

Sign off on the main circuit short check