CED VideoDisc and Player Discussion

[jkravitz]

Dear Colleagues,
I have read most of the forum notes on diagnostics, but I am not entirely clear if the problem of image stall and repeating the image in very rapid fashion is disc or player. It is as if the needle cannot make it to the next groove. My machine is a very second hand SKT 100, with a new stylus.
When it plays the 3 chapters prior to the bad spot, all works well. I have tried several discs, though all are from the same family, so could the previous owner's machine have "marked" the discs in some way?
Just a point of note, when I try to use the chapter search, it will show advancing chapters on the LCD, but it will always return to the current spot on the disc rather than jump ahead.
I am an laser disc collector, but could not pass up the opportunity to experience this wonderful technology.
Let me know what you may advise.
Thank you in advance for the help.
Jay Kravitz

[RT9342]

That's a more unusual problem, but I once had an SGT-200 with a similar problem. I just want to make sure, though, that you are aware that the number on the display is the minute count, not the chapter number. Few discs had chapter encoding, and I believe only the 400 models had chapter search, but most players just deal with the minutes. While it may be possible that the discs got a worn spot about 3 minutes from a bad player, I would be more suspicious that the tonearm in your player is simply getting stuck. This is what my SGT-200 was doing. Try operating it with the cover removed, press fast-forward and if the tonearm is not moving, gently pull it towards the center of the disc (must do this VERY gently on SJT and SKT models, due to the flimsy drive gears that easily break). Then see if if plays from there. And if it moves very freely and still hangs up after a few minutes, check to see if the biggest drive gear isn't already broken. I've come across one with a broken gear before. I'm not quite sure why the minutes would increment on a fast-forward if it's not actually fast-forwarding. I know that the SFT and SGT models use a pot, driven by the tonearm, to approximate the minute count during search (the minute count is normally read off of the disc, but during rapid search the disc is not scanned). But I'm not as familiar with all of the electronics in the SJT and SKT models, so perhaps they may use a timer, rather than a reference pot (I do know that the motor drive during playback is time-based on these models, while it is controlled by stylus sensors in the SFT and SGT models).

[jkravitz]

I did not realize that this was minutes, but in does make sense. I find that this usually happens at 3-4 minute change over. The broken gear concept is interesting, I will look at the gears more closely. I have moved the stylus arm, and it does go on to play from that point. I am not sure if it will hang up again, or play entirely through. I do notice that when this does happen, the gearing to the stylus shudders.
I will pull the stylus and try to move the arm back and forth to "loosen" it.
Thanks for the insights.
Jay Kravitz