Refrigerator display shows E0 and unit may not cool properly or may behave erratically.

Safety first: Unplug the refrigerator from the wall outlet before removing any panels. Do not work on live circuits.

Step-by-step checks:

• Power cycle the unit: Unplug the refrigerator for 5 minutes, then plug it back in. This can clear a temporary logic fault.
• Inspect the main control board connections: Access the rear control compartment (usually behind a metal cover on the back of the unit). Remove the cover and visually inspect the main PCB for burnt spots, bulging capacitors, or corrosion.
• Check wiring harnesses: Gently unplug and re-seat each connector going to the main board, especially the large multi-pin harnesses. Look for bent pins or discoloration.
• Verify proper grounding: Ensure the ground wire is firmly attached to the chassis and the outlet is properly grounded.
• Test operation: Restore power and see if the E0 code clears. If the code returns immediately, the control board is likely defective.

When to replace: If wiring and power supply are good and E0 persists, replace the main control board with the correct Summit part number for your model. If you are not comfortable working with electronics, contact a qualified technician.