1. Double ball bearing, press the fan blade gently by hand repeatedly, the elastic clearance conforms to the assembly drawing, and the spring back is smooth and the pressure is normal.

2. When the concave point of the fan blade stops at a certain pole, it can be started normally by power on, and then the fan blade can be turned forward to the next pole, and the fan blade can be started by power on retest.

3. Current: after power on, discharge the cooling fan vertically to confirm whether the current is within the specified specification.

4. Speed: after power on, the cooling fan shall be placed vertically to confirm whether the speed exceeds the standard, and the outlet air volume is normal and the air outlet direction specification.

5. Fan blade turning: after power on, confirm that the fan blade transfer direction meets the specification: counter clockwise rotation and air outlet direction.

6. Waveform: after the computer determines pass, visually confirm that the frequency band and period of current wave and signal are normal.

7. Super frame: hold the frame with the left hand. After scraping the frame from bottom to bottom at the edge of the test board in a diagonal manner, the abnormal sound of the fan blade hitting the test board or the fan blade stops running indicates that the fan blade exceeds the frame body, which means that the fan blade is not good.

8. Abnormal sound: the fan leaves face down, rotate on the net at a steady speed until the frame is placed vertically, and the fan leaves face up. The abnormal sound is judged by ear hearing. The distance of hearing test is 8-12cm below 5cm and 12-20cm above 5cm (inclusive)

9. Hand feeling test: the middle finger and thumb hold the edge of the frame, turn the fan gently or horizontally and vertically for 45 ° and so on. The degree of vibration is judged: the vibration is judged according to the vibration sample: the hand feeling of the fan is tested: the fan blade can not have jumping movement when running.