"Micro Cooling Fan" power, using test pencil checking metal parts, there should be no leakage phenomenon. He shook his head and shook his head when devices require coherent smooth, low noise, no gap pause, there should be no stagnation or sudden bounces or "giggle" sound phenomenon, "Micro Cooling Fan" shaking his head angle should be greater than 80 to 90 degrees. Requirements can be started at a low gear when no "buzzing" sound, no vibration when the sound "imperfections" sound, fast file running, howling, knock. In the swing position to start with the most low-end, the fan quickly up to speed, particularly when under 0.85 times the rated voltage can be normal start; when changing gear, there are significant changes in the amount of wind; let the fan at high speed operation, and shook his head means work, there should be no apparent unusual noise. Work within 30 minutes, "Micro Cooling Fan" motor without a clear sense of hot (temperature lower motor the better the quality).