Daikin Indoor Unit Wall Mounted Type FTXJ35MV1BW

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

Voltage between (+) and (-) of the power module is approximately 0 V?

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

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

Evaluate the measurement results

Sign off on the power module check

Warning: Disconnect the connectors of the thermistors from the PCB before proceeding

Thermistors disconnected from the PCB

Measure the resistance of each thermistor using a multimeter

If the room temperature thermistor is soldered on a PCB, remove the PCB from the control PCB to measure the resistance

PCB removed from the control PCB

Measure the resistance of the room temperature thermistor

If the connector of indoor heat exchanger thermistor is soldered on a PCB, remove the thermistor and measure the resistance

Indoor heat exchanger thermistor removed

Measure the resistance of the indoor heat exchanger thermistor

Check the connection of connector

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

Check the motor control voltage (pins 4 - 3)

Check the rotation command voltage (pins 4 - 2)

Check the rotation pulse (pins 4 - 1)

Sign off on the fan motor connector output check

EV connector correctly connected to the PCB

Does the EV generate a latching sound when power is turned off and on again?

Continuity confirmed using a multimeter after disconnecting the connector if EV does not generate a latching sound

Check the continuity between the pins

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

Outdoor unit PCB is faulty if continuity is confirmed in step 3

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

Check if the power supply waveform is a sine wave (Fig.1)

Check if there is waveform disturbance near the zero-cross (sections circled in Fig.2)

Sign off on the power supply waveforms check