Freezer beeps and displays E1; temperature rises above set point and compressor may not start or runs briefly then stops.

Safety first: Unplug the freezer from the wall outlet before removing any panels. Use insulated tools and avoid touching live terminals.

Step-by-step checks:

• Power cycle: Disconnect power for 5 minutes, then plug back in. If E1 returns immediately, continue with diagnosis.
• Locate the freezer sensor: On most Sharp upright and chest freezers, the freezer thermistor is clipped to the evaporator tubing or mounted behind an interior wall panel near the top or rear of the compartment.
• Inspect wiring: Remove the interior panel (usually Phillips screws). Check the thermistor leads for cuts, pinches, or corrosion at the connector going to the main control PCB (often located behind the rear service panel or in the control housing).
• Test the thermistor: Disconnect the thermistor from the harness. Using a multimeter set to resistance (kΩ), measure across the two thermistor leads. At room temperature (around 25°C), most Sharp NTC sensors should read roughly 5–20 kΩ (consult the service sheet if available). If the reading is open (OL), shorted (near 0 Ω), or far outside spec, the sensor is faulty.
• Check continuity of harness: With power still disconnected, check continuity from the thermistor connector to the main PCB connector. Repair or replace any damaged wiring.
• Replace the sensor: If the thermistor is out of range, replace it with a Sharp-compatible freezer temperature sensor (match part number from the rating label or parts list). Clip it back to the evaporator line or bracket in the original position and reconnect the harness.
• Evaluate the control board: If a known-good thermistor and wiring are present but E1 persists, the main control PCB sensor input may be defective. Inspect the board for burnt components or corrosion. Replacement of the PCB is typically required and may be best handled by a qualified technician.

Final step: Restore power, set the desired temperature, and monitor for several hours to confirm that the E1 code does not return and that the freezer reaches and maintains the correct temperature.