Got a Nak CPC-4A as parts unit and trying to fix it. When I got it the laser was missing. Tried searching under the boards and no luck. Bought a working PD4300 and swapped the lens. Thought it would fix it but seems the same issue. The CD goes in and after 2-3 secs gets back into the disc magazine. I checked that the laser does move in and out for a while and when I tried looking closely (i know it was not recommended) I do see a faint red for a while and goes off. The motor once I noticed it did spin for a while. The issue to summarize is the CD gets in, doesnt latch up to top plate, NO spin and then gets back into magazine. Anyone with similar issue or tips to fix. Thanks
Sounds like the transport belt is slipping and not fully engaging the CD to clamp with the spindle. Also, if the spindle motor is old enough ie worn brushes, the CD will spin up but not play. You have to check and see if the voltage across the spindle motor is within expected range of what the drive servo wants to be at. I don't remember what that voltage is supposed to be, but I believe if its over 3V, the motor isn't generating enough torque to reach needed rpms at startup.
Thank you. the mechanism doesnt have much of belts as its magazine loaded. I have two set of the laser assemblies that has the motors. One with lens and the other that fell off. So swapping the working lens to other had the same result. I checked the service manual but most of the tests are with osciloscope which I dont have and neither know how to use it.
I would change the spindle motor. A quick test to verify its bad is to disconnect it from the drive servo and spin it up manually with a 9 v battery for 10 sec, then reconnect and retest.