Freezer beeps and displays E1, temperature rises above set point and will not cool properly.

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:

• 1. Power reset: Unplug the freezer for 5 minutes, then plug it back in. If E1 returns within a few minutes, continue with diagnosis.
• 2. Locate the cabinet thermistor: On most Toshiba upright freezers, the cabinet (compartment) thermistor is clipped to the evaporator cover or mounted on the liner wall behind a small plastic cover. Remove the inner panel carefully to access it.
• 3. Inspect wiring: Check the thermistor leads for cuts, pinches, or signs of moisture damage. Ensure the connector is fully seated on the main control PCB (usually in the top or rear control box).
• 4. Test the thermistor: With the freezer unplugged, disconnect the thermistor from the harness. Measure resistance with a multimeter at room temperature (around 25°C). A typical Toshiba NTC thermistor will read roughly 5–10 kΩ at 25°C (consult the service sheet if available). If it reads open (OL) or near 0 Ω, it is defective.
• 5. Check at the PCB end: If the thermistor tests good at the sensor, test resistance from the PCB connector to rule out a broken harness.
• 6. Replace faulty parts: If the thermistor or harness is faulty, replace it with a Toshiba-compatible cabinet thermistor assembly. If the sensor and wiring are good but E1 persists, the main control PCB may have a failed input circuit and should be replaced.

When to call a technician: If you are not comfortable removing inner panels or testing resistance, or if the main PCB appears to be faulty, contact an authorized Toshiba service center.