Daikin Wall-Mounted Indoor Unit CTXS07JVJU

Warning: This procedure requires trained personnel with PPE!

Install the inverter checker 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 checker without touching each other?

Activate the power transistor test operation from the outdoor unit

Forced operation [ON/OFF] switch pressed for 5 seconds?

Diagnose according to 6 LEDs lighting status

Disconnect the connectors of the thermistors from the PCB

Thermistors disconnected successfully

Measure the resistance of each thermistor using tester

The relationship between normal temperature and resistance is shown in the table and the graph below

The room temperature thermistor is directly mounted on the display PCB. Remove the display PCB from the control PCB to measure the resistance.

Display PCB removed successfully

Measure the resistance of the room temperature thermistor

When the indoor heat exchanger thermistor is soldered on the PCB, remove the thermistor and measure the resistance.

Indoor heat exchanger thermistor removed successfully

Warning: Ensure that the voltage between (+) and (–) of the power module (PM1) is approx. 0 V before proceeding.

Voltage between (+) and (–) of the power module (PM1) is approx. 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 terminals of the power module and the terminals of the compressor with a multi-tester.

Enter the resistance measurement

Evaluate the measurement results

Sign off on the power module check

Control voltage between the pins 3 - 4

Rotation command voltage between the pins 2 - 4

2 pulses (0 ~ 15 VDC) are output at the pins 1 - 4 when the fan motor is rotated 1 turn by hand

With the power on, operation off, and the connector connected, check the following

Output voltage of about 5 V between pins 1 and 3

Generation of 3 pulses between pins 2 and 3 when the fan motor is operating