To analyze the failures should be caused by the laser head and its components, to open the cover, plug in the power, take the 5th after first tracks, can observe bald to the corresponding point, bald-headed then reset. Repeat test machine, occasionally played. This machine has been used for almost 6 years, it is estimated that aging bald are more likely to, try to increase the laser power is invalid. Bald-headed analysis to the appropriate position, and turned the power of the laser tube, so ruled out the possibility that transmission blocking and laser tube aging. Then check cable and plug of laser head, estimated most likely due to bald poor contact caused by traction during the move. Use pliers to gently pull cable and outlet, results cannot be played. Unscrew the movement screws, turning movement, finds a very obvious on the line creases, stripping and wire and surface hardening. Unplug the cable, multimeter to Rx1 block measuring 3 line resistance is infinite, open circuit. Replaced with a new cable, be fixed with silicone and try power on machine fault completely ruled out.