Daikin Air Conditioner RX30NMVJU

Warning: This procedure requires trained personnel with PPE!

Main circuit checked for short circuit?

Warning: Never touch any live parts during the procedure.

Note: The surface of the test points (DC–) may be covered with the coating.

Firm contact between the multimeter probes and the test points?

Sign off on the capacitor voltage check

Warning: This check requires trained personnel with PPE!

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

Is the power supply waveform a sine wave?

Is there waveform disturbance near the zero-cross?

Sign off on the power supply waveforms check

Warning: Ensure the voltage between (+) and (-) of the diode bridge (DB1) is approximately 0 V before proceeding

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 less than 1 kOhm?

If the resistance is less than 1 kOhm, a 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 before proceeding

Thermistors disconnected from the PCB

Note: The room temperature thermistor is soldered on the PCB

Connector to the control PCB disconnected before measuring the resistance

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

Indoor heat exchanger thermistor removed

Resistance of the indoor heat exchanger thermistor

Sign off on the thermistor resistance check

Warning: This procedure requires trained personnel. Always ensure power is off before starting.

If power is not off, turn it off and wait until the charged voltage of the built-in smoothing electrolytic capacitor drops to 10 VDC or below.

Is the charged voltage of the built-in smoothing electrolytic capacitor 10 VDC or below?

Install an inverter analyzer instead of a compressor.

Inverter analyzer installed correctly?

Activate power transistor test operation from the indoor unit.

Power transistor test operation activated?

Sign off on the inverter analyzer check