Daikin Indoor Unit Wall Mounted Type Air Conditioner ATX20K2V1B

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

Control voltage between the pins 3 - 4

Rotation command voltage between the pins 2 - 4

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

Rotation pulses at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

Outdoor fan motor functioning properly?

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 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 ∞ or less than 1 kΩ?

If the resistance is ∞ or less than 1 kΩ, short circuit occurs on the main circuit.

Sign off on the main circuit short check

Warning: Disconnect the connectors of the thermistors from the PCB

Measure the resistance of each thermistor using a multimeter

When the room temperature thermistor is soldered on a PCB, remove the PCB from the control PCB

Measure the resistance of the room temperature thermistor

When the connector of indoor heat exchanger thermistor is soldered on a PCB, remove the thermistor

Measure the resistance of the indoor heat exchanger thermistor

Sign off on the thermistor resistance check

Fan motor wire breakdown / short circuit check

1. Check the connector for connection.

3. Check if each resistance at the phases U - V and V - W is 90 Ω ~ 100 Ω (between the pins; 12 - 9, and between 9 - 6).

1. Check the connector for connection.

2. Check the motor control voltage is generated (between the pins 2 - 3).

1. Check the connector for connection.