Mini fridges may not cool effectively due to issues within the refrigeration system (compressor, condenser/evaporator coils, fan motor, refrigerant) or temperature-regulating components (thermostat, evaporator, temperature probe, door gasket). External factors such as power supply, wiring, or fuses can also impact performance. Understanding these interconnected components and external influences helps identify and troubleshoot the root cause of ineffective cooling in mini fridges.