Refrigerator not cooling, display shows H01 alarm or blinking, 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 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 resistance between compressor terminals. All windings should be similar in resistance and not 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 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.