Daikin Indoor Unit Wall Mounted Type FTXJ25MV1BS

Warning: Ensure the voltage between (+) and (-) of the power module is approximately 0 V before proceeding.

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?

Measure resistance between the (+) or (-) terminal of the power module and the U, V, or W terminal of the compressor with a multimeter.

Enter the resistance measurement

Evaluate the measurement results

Sign off on the power module 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

FAN operation selected with the Mode button on the remote controller?

1. Check that the control voltage between the pins 10 - 11 is 15 VDC.

2. Check if the Hall IC generates the rotation pulse (0 ~ 15 VDC) 4 times between the pins 10 - 12, 10 - 13, when the fan motor i/s manually rotated once.

Make sure that the voltage of 320 ± 30 V is applied.

1. Set operation off and power off. Disconnect the connector S70.

2. Check that the voltage between the pins 4 - 7 is 320 VDC.

3. Check that the control voltage between the pins 3 - 4 is 15 VDC.

Warning: Disconnect the connectors of the thermistors 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

Measure the resistance of the room temperature thermistor

If 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

EV connector correctly connected to the PCB

Does the EV generate 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

If there is no continuity between the pins, the EV coil is faulty

If the continuity is confirmed, the outdoor unit PCB is faulty

Sign off on the electronic expansion valve check