Daikin Indoor Unit Ceiling Mounted Cassette Type Heat Pump FFQ12Q2VJU

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

Check the continuity between the pins

Outdoor unit PCB (main PCB) is not faulty

Sign off on the electronic expansion valve 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

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

Note: The data is for reference purpose only

Room temperature thermistor removed from the control PCB

Measure the resistance of the room temperature thermistor

Indoor heat exchanger thermistor removed

Measure the resistance of the indoor heat exchanger thermistor

Sign off on the thermistor resistance 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 power transistor test operation from the outdoor unit

FAN operation set using the remote controller?

Check No.16: Make sure that the voltage is within 320 VDC.

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?