Daikin Indoor Unit Wall Mounted Type Air Conditioner FTX50KMV1B

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

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

Indoor heat exchanger thermistor removed

Measure the resistance of the indoor heat exchanger thermistor

Ensure that the voltage of 320 + 100 V ~ 320 - 50 V is applied.

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.

4 rotation pulses (0 ~ 15 VDC) at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

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)

If the voltage is not about 0 V, stop the procedure and report the issue

Enter the resistance between the pins of the DB1

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

Does the main circuit have a short circuit?

Sign off on the main circuit short 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 indoor unit

Pressed the center of the TEMP button and the OFF button on the remote controller at the same time?

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