I found this manual to be complete in every detail. Besides the schematic it has a complete set of alignment instructions which are easy to understand. It also includes a complete parts list as well as an explanation of how the power supply and safety shutdown circuits operate. Even a schematic of the tuner is included.
The product was good and just what I needed, however I had moderate difficulty with the down load because the sight would not recognize my pass word. I was finally given a direct link to the manual and that worked.
It is an very good and clear scanned service manual.
Text excerpt from page 74 (click to view)
The pickup transmission initial operation is carried out to determine the initial position by transmitting the pickup to the innermost position once (start-limit switch (pin 4 of CN503) develops "L".) and to the external direction at low speed (start-limit switch develops "H", turning off the switch.).
Pickup (P.U.) transmission initial operation does not occur.
Does pulse of 1.65V 1.65V develop at pin 162 of IC401? Y Check feed gear.
Check BUS between IC401 and IC605 and oscillation.
"No disc" misjudgement display of disc presence.
Does lens move with UP/DOWN full stroke in focus direction? Y
Is laser current normal? Y
Does RFSB signal develop more than 0.3V?
Y Check peripheral circuit of IC605. Does focus search voltage of 1.65V 0.4V develop at pin 23 of IC503 (E544)? Y Does search signal output at both edges of focus coil? (Pins 15 to 18 of CN501) Y Check pickup head and wiring. N N Check IC401. Replace pickup head. Check IC502. Lens cleaning.