A1

Daikin Indoor Unit Main PCB Failure

Indoor unit does not start or stops with A1 error on Daikin controller

Safety Warning

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

Shorted components on indoor PCB, Power surge damage, Corroded PCB due to moisture, Loose connectors on indoor PCB

How to Fix / Troubleshooting

Safety first: Disconnect power at the breaker and wait several minutes for capacitors to discharge before touching the PCB.

Checks:

Remove the indoor unit front cover and carefully inspect the main PCB for burn marks, corrosion, or loose connectors.
Reseat all plug-in connectors firmly, ensuring correct orientation.
Check that no wiring harness is pinched or damaged by the unit casing.

Technician actions:

Measure supply voltages on the PCB according to the Daikin service manual.
If the PCB shows visible damage or incorrect voltages, replace the indoor main PCB with the exact Daikin part number.
After replacement, reconfigure any model-specific settings as required.

Repair Difficulty

Hard 4/5

Required Part

Indoor Unit Main PCB

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