Problem Description：Rattling
Reason Analysis：
1）The position of the motor is unbalanced
2）Motor belt deviation
3）Rollers rattling
4）Motor belt grinding to the lower side of the motor cover
5）Motor blade grinding to the top cover of the motor
6）Motor blade broken
7）Running board screws are not tightened
8)There is a foreign matter under the running belt
Solutions:
1)Motor below the cover has two lock motor screw holes. first of all, the left screw counterclockwise rotation to loosen the screw, and then the right screw clockwise locking screw, so that the motor body and the spacing between the running belt 10mm or so, and then clockwise locking the left screw，Note: When locking, the main body of the motor needs to be level with the running belt, not skewed, otherwise it will affect the life of the small belt or produce a strange sound. Then install the motor cover, starting the treadmill again to confirm whether there is an abnormal sound of friction.
2)Adjusting motor belt
3)Replacement of front or rear rollers
4)Trimming of the lower motor cover where cause friction
5)Confirm that there is no wear on the fan edge of the motor. If there is wear, it means that the motor fan is rubbing against the edge of the electronic display The two screws at the bottom of the motor were not locked in right place, resulting in a small space between the motor and the roller. After assembling the motor cover, the fan will rub against the motor cover when running，Follow the plan ① to operate, using scissors or utility knife to trim the motor fan edge 1-1.5mm and a circle of friction parts. The trimmed fan does not affect the motor performance and treadmill function at all.
6)Replace the motor blade
7)Tighten the screws
8)Clean up foreign objects