Daikin Indoor Unit Multi-Split Type Air Conditioner FVXS18NVJU

Warning: This procedure requires trained personnel with PPE!

Install an inverter analyzer 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 analyzer without touching each other?

Activate the power transistor test operation from the outdoor unit.

Forced cooling operation ON/OFF switch pressed for 5 seconds?

Diagnose according to 6 LEDs lighting status.

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 indoor fan motor is operating

If OK in both steps (1) and (2)

Warning: This procedure requires trained personnel with PPE!

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

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)

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 ∞ or less than 1 kΩ?

If the resistance is ∞ or less than 1 kΩ, short circuit occurs on the main circuit.

Sign off on the main circuit short check

Warning: This procedure requires trained personnel with PPE!

Main circuit checked for short circuit?

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

Sign off on the capacitor voltage check