Daikin Indoor Unit Wall Mounted Type FTX15NMVJU

EV connector correctly connected to the PCB

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

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 faulty if continuity is confirmed

Sign off on the electronic expansion valve check

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.

Connector disengaged successfully?

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

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)

Measure the resistance between the pins of the DB1

Enter the resistance between the pins of the DB1

Is the resistance infinity or less than 1 k(omega)?

If the resistance is infinity or less than 1 k(omega), a short circuit occurs on the main circuit.

Sign off on the main circuit short check

Warning: Disconnect the connector of thermistor ASSY from the PCB before proceeding

Enter the resistance value of the thermistor

Select the expected resistance value

Does the measured resistance match the expected value?

If the measured resistance does not match the expected value, replace the thermistor

Sign off on the thermistor resistance 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.

If fuse is melted, check the outdoor fan motor for proper function.