Only the noise stopped, all the normal operation. Doubted that machine mechanical parts loose or abnormal movements. Open the shell after electrical switches to observe the mechanical movement for many times, no abnormalities are found. After normal, turned on the power switch, accordingly, to operate and can perform operations after the confidential, such as noise, and found noise source is main motor. Without electricity, hand upon the leading motor also there was a noise, pushing up on the main motor, main shaft displacement of the up and down too much. The reason is: move upward thrust adjusting screw. Reset the screws. The machine back to normal. As shown in figure, the phenomenon applies M how.RG9service manual download site