Daikin Indoor Unit Floor Standing Type Air Conditioner FDMQ12WVJU9

Warning: This check requires trained personnel with PPE!

Measure the power supply waveform between No. 1 and No. 2 on the terminal strip

Is the power supply waveform a sine wave?

Is there waveform disturbance near the zero-cross?

Sign off on the power supply waveform 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 following pins

EV coil is not faulty if there is continuity between the pins

Outdoor unit PCB (main PCB) is not faulty if continuity is confirmed

Sign off on the electronic expansion valve check

Warning: This procedure requires trained personnel with PPE!

Disconnect the connector of thermistor ASSY from the PCB to measure the resistance between the pins using multimeter.

Enter the measured resistance value of the thermistor

Does the measured resistance value match the listed value?

To check the thermistor soldered on a PCB, disconnect the PCB from other PCB/parts, and measure the resistance between the both ends of soldered thermistor.

Enter the measured resistance value of the soldered thermistor

Does the measured resistance value of the soldered thermistor match the listed value?

Note: When replacing the defective thermistor(s), replace the thermistor as ASSY.

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 the power transistor test operation from the outdoor unit

Center of TEMP button and OFF button on the remote controller pressed at the same time?

Voltage between (+) and (-) of the diode bridge (DB1)

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

Resistance between the pins of the DB1

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

Short circuit on the main circuit?

Sign off on the main circuit short check