Daikin Outdoor Unit Heat Pump For Split System RXS35L3V1B

1. Check the connector connection.

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

(1) Output voltage of about 5 V between pins 1 and 3.

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

If NG in step (1) => Defective PCB => Replace the PCB (control PCB).

If NG in step (2) => Defective Hall IC => Replace the fan motor.

If OK in both steps (1) and (2) => Replace the PCB (control PCB).;

Warning: This procedure requires trained personnel with PPE!

If power is not turned off, stop the procedure and turn off the power

Install an inverter analyzer instead of a compressor

Warning: Make sure the charged voltage of the built-in smoothing electrolytic capacitor drops to 10 VDC or below before carrying out the service work

Remove the terminals from the compressor

Connect the terminals to the terminals of the inverter analyzer

Warning: Be careful not to let the terminals (U,V,W) touch each other. Otherwise, high voltage is applied

Activate the power transistor test operation from the outdoor unit

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

Enter the voltage between (+) and (-) of the diode bridge (DB1)

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

Enter the resistance between the pins of the DB1

Does the resistance indicate a short circuit?

Sign off on the main circuit short check

EV connector correctly connected to the PCB

EV generates 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 pins

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

Outdoor unit PCB is not faulty if continuity is confirmed

Sign off on the electronic expansion valve check

Warning: Disconnect the connectors of the thermistors from the PCB before proceeding

Thermistors disconnected from the PCB?

Measure the resistance of the room temperature thermistor using multimeter

If 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

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

Indoor heat exchanger thermistor removed from the PCB?

Measure the resistance of the indoor heat exchanger thermistor