Freezer not cooling at all; interior is warm and compressor is not running.

Critical safety warning: Unplug the freezer before removing the rear panel or touching compressor wiring. High voltage is present.

Steps to diagnose no cooling with silent compressor:

• Verify power: Confirm the outlet has power by plugging in another device. Check that the freezer's power cord and plug are intact.
• Check control settings: Ensure the temperature control is not set to OFF or the warmest setting. On mechanical-dial Costway freezers, turn the dial from OFF to mid-range and listen for a click.
• Listen for relay click: After plugging in, listen near the compressor for a brief click. No click may indicate a control or relay issue.
• Access compressor compartment: Unplug the unit and remove the rear lower panel. Inspect the PTC start relay and overload protector on the compressor for burns or loose connections.
• Test continuity: With a multimeter, check continuity through the overload and start relay. Replace any open components with compatible Costway parts.
• Check wiring harness: Ensure the harness from the control board to the compressor is not damaged or disconnected.
• Control board check: If start components are good but the compressor never receives power, the main control board or thermostat may be faulty and require replacement.

When to call a technician: If the compressor receives proper voltage but does not start or trips the overload repeatedly, the compressor is likely failed and needs professional replacement.