Daikin Air Conditioner 4MXL36TVJU

Describe any abnormal stops observed

Install an inverter analyzer instead of a compressor

Ensure charged voltage of built-in smoothing electrolytic capacitor is 10 VDC or below

Activate the power transistor test operation from the outdoor unit

Press the forced cooling operation ON/OFF switch for 5 seconds

Disconnect the connector of thermistor ASSY from the PCB

Disconnect the PCB from other PCB/parts if thermistor is soldered

Measure the resistance of Thermistor 1 using multimeter

Measure the resistance of Thermistor 2 using multimeter

Measure the resistance of Thermistor 3 using multimeter

Does the resistance of Thermistor 1 match the specified value?

Verify EV connector insertion and matching

Power Cycle and Latching Sound Check

Turn the power off and on again

Do all EVs generate a latching sound?

Does any EV not generate a latching sound?

Disconnect the connector of the EV that did not generate a latching sound

Check continuity between pins 5 - 1, 5 - 2, 5 - 3, 5 - 4 using a multimeter

Ensure voltage between (+) and (–) of the diode bridge (DB1) is about 0 V

Measure the resistance between the pins of the DB1

Is the resistance ∞ or less than 1 kΩ?

Remove the top plate (10 screws)

Remove the right side plate (6 screws)

Remove the front plate (1 screw)

Remove the shield plate (2 screws)

Measure resistance under refrigerant pipe cover

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?