Unit stops with F99; inverter module protection.

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 inverter power module, Internal PCB fault, Severe power surge damage

Warning: Do not attempt to repair the inverter module at component level.

Steps:

1. Power reset: Turn off power for 10 minutes, then restore and test once.
2. If F99 reappears: Leave the unit off and contact a Panasonic-authorized technician.

The usual remedy is replacement of the outdoor inverter PCB assembly.

Professional Required 5/5

Outdoor Inverter PCB

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