Daikin Outdoor Unit Ceiling Mounted Cassette Type Heat Pump RX09RMVJU9

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 (main PCB) is faulty if continuity is confirmed

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

Thermistors disconnected from the PCB

Measure the resistance of the room temperature thermistor

Note: The data is for reference purpose only

Room temperature thermistor removed from the PCB

Measure the resistance of the indoor heat exchanger thermistor

Indoor heat exchanger thermistor removed from the PCB

Sign off on the thermistor resistance check

Check No.20: Check to make sure that the voltage between (+) and (–) of the diode bridge (DB1) is approximately 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 is  or less than 1 k?

If the resistance is  or less than 1 k, short circuit occurs on the main circuit.

Sign off on the main circuit short check

Check No.22: Make sure that the voltage between (+) and (–) of the power module is approximately 0 V before checking.

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.

Compressor harness connector disconnected from the outdoor unit PCB

Follow the procedure below to measure resistance between the terminals of the power module and the terminals of the compressor with a multimeter.

Enter the resistance measurement between the terminals of the power module and the terminals of the compressor

Evaluate the measurement results

Sign off on the power module check

Check the connection of connector

Check motor power supply voltage output (pins 5 ~ 8)

Check motor control voltage (pins 5 ~ 4)

Check rotation command voltage output (pins 5 ~ 3)

Check rotation pulse input (pins 5 - 2)

Sign off on the Indoor Fan Motor Connector Output Check