Wine cooler not cooling at all; interior stays at room temperature and compressor does not run.

Safety warning: Unplug the wine cooler before accessing the compressor or control board. High voltage is present in these circuits.

Steps to diagnose no cooling:

• Check power and display: Confirm the unit powers on, the display lights, and the temperature is set correctly. Verify the outlet with another appliance.
• Listen for compressor: With the rear panel removed, plug in the unit and listen for a humming or clicking from the compressor area. Unplug again before touching anything.
• Inspect start device: Remove the plastic cover on the compressor terminals. Check the PTC start relay and overload protector for burn marks, cracks, or rattling pieces.
• Test continuity: With a multimeter, test the overload protector and start relay for continuity as per their specifications. Replace if open or visibly damaged.
• Check wiring from control board: Ensure the harness from the main control PCB to the compressor is intact and firmly connected.
• Replace start device: Install a Haier-compatible compressor start relay and overload protector if faulty. Refit the terminal cover securely.
• Re-test: Restore power and observe whether the compressor now starts and cooling resumes.

Note: If the compressor still does not start and the control board is sending power, the compressor itself may be failed and will require professional sealed-system service.