Very nice video. I have thought of doing them, but the time required to make something that polished is extensive.
mips wrote:
Scanning through the service documentation seems to indicate that a service mode can be entered and you can manually operate the focus but I'm not entirely sure what that might accomplish as I don't know where to attach a scope to monitor the signal form the detector, or what I'm expecting to see on the scope without a test disc.
I have never worked on this model, but I read through the SM.
When you press play, FOCUS ON is sent from CONT to VSOP and FOCUS LOCK is sent back. If focus can't be locked (thus no FOCUS LOCK response is sent), it tries four times at one second intervals. You should see (or hear in your case) four attempts. LASER ON is sent at the same time of FOCUS ON.
As the focus motor raises the lens, tracking error is created and then focus error.
TP1 is Focus Error, TP5 is tracking error. You can turn off tracking by grounding TP8 and tangential (on later players, this is called tilt) by grounding TP 1/6 (Not sure if 1/6 means pin 1 on a 6 pin connector).
Referencing the troubleshooting section of SM (Page 69), check for a "S-shape curve" at TP1 of at least 2V peak to peak. The other note is something about a "bight" and paper I do not understand in regards to slider beam axis. TP-7 and 12 should be within 20mV of 0V. It then mentions adjusting focus gain, but I would skip over that and check Z1, Z3, Q1 in focus servo. I read Q1 is closed when Q7 is low and Q6 is high.
More or less what I would try. Double check all of the above before actually attempting. It would be best to take a look at the focus motor to make sure something isn't mechanically wrong there first.
Don't worry about a test disc. Any CAV will suffice for the above, but you could still order GGV1016 from instrumental parts a few months ago which would be helpful.