Unit stops with F90; compressor may not start or may stop quickly.

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Faulty inverter compressor, Defective outdoor inverter PCB, Low supply voltage, Loose power connections

Warning: High-voltage inverter circuits are dangerous. Limit checks to visual inspection and basic electrical safety.

Steps:

1. Check supply voltage: Ensure the AC supply matches the unit's rated voltage and is stable.
2. Inspect power terminals: With power OFF, tighten L/N (and L1/L2/L3 for 3-phase) terminals at the outdoor unit.
3. Visual PCB check: Look for burnt or cracked components on the inverter PCB.

If F90 persists, a technician must test the compressor and inverter PCB and replace the defective part.

Professional Required 5/5

Outdoor Inverter PCB

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