Fan replacement in blockchain machines involves removing the faulty or inefficient fan that helps regulate the machine’s temperature and installing a new, high-quality unit to ensure proper cooling and airflow. The process requires disconnecting the existing fan’s wiring, securing the new fan in place, and confirming that it operates correctly to maintain optimal temperatures. A properly functioning fan is crucial to prevent overheating, which can significantly impact performance, reduce hashing efficiency, and lead to potential hardware damage.