Freezer not cooling at all; interior is warm, compressor not running, but lights and display work.

Safety first: Unplug the freezer before accessing the compressor compartment. Do not touch live terminals.

Basic checks:

• Verify the temperature setting is not at its warmest position or in demo mode (if applicable).
• Listen for any humming or clicking from the compressor area when the unit is powered (before unplugging). Repeated clicking suggests a start issue.

Inspect start components:

• Remove the rear lower panel to access the compressor.
• Remove the plastic cover over the compressor terminals and inspect the start relay/PTC and overload for burn marks or melted plastic.

Electrical tests:

• With power disconnected, test the overload for continuity and the PTC relay for appropriate resistance (not open, not a dead short).
• Check continuity of wiring from the main PCB to the compressor assembly.

Corrective actions:

• Replace start relay/PTC and overload: If either is defective, install Blomberg-compatible replacements.
• Check control board output: If start components and wiring are good but the compressor never receives power, the main control board may be faulty and require replacement.
• If compressor windings are open or shorted, the compressor is failed and must be replaced by a certified technician.

Test: Reassemble, restore power, and confirm that the compressor starts and the freezer begins cooling within a few hours.