Check the CD machine core circuit board, no exceptions. Analysis of the machine into the disk drive circuit, when inserted into the CD disc. The disc blocks the movement of photoelectric tubes and a CD of the upper of the photoelectric receiving tube circuit of signaling pathways, CD machine core microprocessor detects the signal, the output load motor start signal, will make the loading motor CDS suction within the movement. Because occasionally discs can be inhaled, and reading is normal, circuit is normal. Cotton swab to wipe the surface of the photoelectric tube after commissioning, troubleshooting.baqservice manual download site