Washer-dryer combo shows F40 and may not start; communication or power issue indicated.

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

Defective main control board, unstable line voltage, wiring harness issue, internal ACU failure

Safety first: Turn off power at the breaker and unplug the unit.

Step-by-step checks:

Verify supply voltage and polarity: Ensure the outlet is wired correctly and provides stable voltage.
Inspect ACU connections: Check all connectors on the main control board for tightness and signs of overheating.

When to replace: If external power and wiring are correct, replace the main control board (ACU).

Hard 4/5

Main Control Board (ACU)

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