The refrigerator is not cooling, the display shows an H01 alarm or is blinking, and the compressor does not start.

Safety first: Unplug the refrigerator from the wall outlet before removing any panels. High voltage is present at the inverter and compressor terminals.

• Step 1 – Power reset: Disconnect power for 5–10 minutes, then reconnect. If H01 clears temporarily and returns, continue with the checks.
• Step 2 – Inspect rear compartment: Pull the unit away from the wall. Remove the lower rear service cover to access the compressor and inverter module (usually a small PCB mounted near the compressor on Panasonic inverter models).
• Step 3 – Check wiring harness: Inspect the multi-pin connector from the main control board to the inverter PCB. Look for burnt pins, corrosion, or loose plugs. Reseat all connectors firmly.
• Step 4 – Visual check of inverter PCB: Look for burn marks, bulged capacitors, or cracked solder joints on the inverter board. If any damage is visible, the inverter PCB should be replaced.
• Step 5 – Compressor test (advanced): With power still disconnected, use a multimeter to measure the resistance between compressor terminals. All windings should have a similar resistance and not be shorted to ground. If windings are open or shorted, the compressor is faulty and requires professional replacement.
• Step 6 – If wiring and compressor test good: The inverter PCB or main control PCB is likely defective. Replacement typically requires a qualified technician due to the high-voltage and refrigerant system proximity.

Do not attempt to bypass the inverter or run the compressor directly from mains power; this is dangerous and will destroy the compressor.