Wine cooler beeps and displays E5; unit may not cool or may shut down shortly after starting.

Safety: Unplug the wine cooler. Do not touch exposed terminals while energized.

Diagnostic steps:

• Identify cooling type: Many Koolatron wine coolers are thermoelectric (Peltier-based), while some larger units are compressor-based. Look through the rear grille: a small square metal module with heat sinks indicates thermoelectric; a black metal canister indicates a compressor.
• Check wiring: Remove the rear cover. Inspect all connectors from the control board to the compressor or Peltier module. Ensure they are fully seated and not burnt.
• Look for burn marks: Examine the control board for burnt spots, swollen capacitors, or cracked solder joints near the power relays or MOSFETs.
• Test Peltier module (if applicable): Disconnect the module and measure resistance across its leads. A typical module will show a few ohms. Infinite (open) or 0 Ω indicates a bad module.
• Test compressor (if applicable): For compressor models, check that the compressor is not shorted to ground and that the start device is intact. This is more advanced and may require a technician.
• Replace failed part: If the Peltier module is defective, replace it with a compatible Koolatron thermoelectric (Peltier) cooling module. If the board is visibly damaged or the relay is stuck, replace the main control board.