Daikin Indoor Unit Multi-Split Type Air Conditioner CTXG12QVJUS

Warning: This procedure requires trained personnel with PPE!

Main circuit checked for short circuit?

Warning: Never touch any live parts during the procedure.

Ensure firm contact between the multimeter probes and the test points.

Sign off on the capacitor voltage check

EV connector correctly inserted in the PCB

All EVs generate a latching sound after power cycle

If any EV does not generate a latching sound, proceed to next step

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

If no EV generates a latching sound, the outdoor unit PCB is faulty

Warning: This check requires trained personnel with PPE!

Enter the power supply waveform measurement between No. 1 and No. 2 on the terminal board

Is the power supply waveform a sine wave (Refer to Fig.1)?

Is there any waveform disturbance near the zero-cross (Refer to sections circled in Fig.2)?

Upload a photo of the measured waveform

Sign off on the power supply waveform check

Warning: Ensure that the voltage between (+) and (–) of the power module is about 0 V before proceeding

Voltage between (+) and (–) of the power module is about 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

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: 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

When the room temperature thermistor is soldered on a PCB, remove the PCB from the control PCB to measure the resistance.

Room temperature thermistor removed from the 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 and measure the resistance.

Indoor heat exchanger thermistor removed from the PCB

Measure the resistance of the indoor heat exchanger thermistor