This machine use frequency is high, the use of time more than two years, an estimated to the aging time. Open the chassis, set in the empty machine video reproduction, carefully listening to a "om" sound, found that is the sound of the drum. Stop rotating drum with the hand, I don't feel very flexible, estimation is drum rotational resistance playback as a noise caused by belt and automatic stop. Remove the top of the drum three small screws. Gently remove the cover plate, between plate and axis of find a small steel ball. Use a magnifying glass to observe carefully, the steel ball is deformation, because of the market can't find such a small steel ball, trial round bead pen substitution, and between the drum and the drum shaft in holes on drop a few drops of sewing machine oil, installed on the cover plate. Pay attention to tighten the cover three screw not too tight, when the space above the drum can be close to the original, because the new change of ball-point pen steel ball slightly bigger than the original machine with a steel ball. Installed rotating drum operation is very flexible, electricity of commissioning, "om" sound disappear, this time with one track exactly like trying to put, if there is noise with up and down, to adjust the entry or exit guide pin slightly.ehSservice manual download site