The machine spindle can turn, but can't read TOC (directory), the screen will display "NO DISC". This failure is laser head dirt or caused by aging, if by laser head cleaning and fine tune the laser power is still not back to normal, replace the new laser head. The new laser head is not changed, and only through the change of certain circuit parameters, to make the laser head "shining youth", and prolong the life of the laser head:tkSservice manual download site
Using Samsung SEC-888 movement VCD-2173 type machine motherboard, RF signal processing by KB9223, DSP chip is used KS9284 and laser head with Samsung SOH-AAU.tkSservice manual download site
This machine out of the warehouse normal, there are focus movements, there are laser shot, but the spindle does not turn, the screen is DISC NO ".tkSservice manual download site
In the playback status, the {65}{66} pin voltage of the KB9223 is lower to 2.46V (normal 2.53V), the analysis of the laser head aging, the signal output is weakened. At the ends of the R1 ~ R4, a 56K resistor is respectively connected in order to increase the output range of the laser head.. With the electric test machine, the reading dish is normal and can play normally..tkSservice manual download site