CED VideoDisc and Player Discussion

[jjones7]

I think I broke a stylus in my player the other day by trying to play a VERY beat-up disc (completely foolish on my part - it was a disc I got off eBay that appeared to be from a public library long ago). Anyway, I got maybe 3 minutes into the disc, lots of skipping and then the picture and audio completely stopped and the counter went to two dashes. I assume that means the stylus isn't getting any kind of information off the disc. I tried another stylus on a different disc and everything played fine. So I'm guessing that something about the rough playback broke the stylus. (Which I believe is the one that came with the machine when my parents bought it in 1981 - 42 years probably isn't too bad for this cartridge!)

Anyway, anyone have any thoughts on what, if anything, I can do to clean up or repair this stylus? I have an email out to cedatum but haven't heard back yet.

I guess this is what I get for trying out a rough-looking disc from a random eBay seller....

[jsdspif]

I'm curious how this turned out for you? one of these days I more than likely will have cart's in need of repair also and am wondering how things worked out with yours. Thanks

[jjones7]

Well, aside from feeling foolish in a "I should have known better than to push a disc in without inspecting it" way, I found that my stylus won't work even after gently cleaning with alcohol. I'm not sure what the issue is with it, as I can't tell from the naked eye, so I've put in a 'new' out-of-the-box cartridge. With the new cartridge, my discs are WAY more vibrant in color.

However:

Every disc I put in, and every other stylus I use: the machine doesn’t want to start right at the beginning, it starts around 30 seconds or so in (around halfway through the RCA fanfare, for example). And then it will play beautifully for a couple minutes then it’ll skip a bunch, go back a few seconds and then you can hear the arm moving to a new groove to kinda get out of the skipping rut that it’s in. I hope that makes sense - I don’t think it’s the stylus and I know it’s not the discs, since it does it with every disc.

Josh at CEDatum advised that this is likely two things: the set screw at the back of the machine needs adjustment in order to get the discs to play at the beginning, and the small belt that moves the cartridge's arm assembly back and forth is likely dirty or needs replacing. I haven't taken the machine apart yet to inspect that belt, but I did get a replacement from him. When I do that I'll also adjust the set screw on the back. It's amazing that one crummy disc wrought such havoc on the machine!

[jsdspif]

i had that start 30 second in problem as i was working on a player (I think)? I sent the cartridge in and there was a problem with the cart ,i want to say out of alignment but I can't remember. But it was just strange I'm playing a disc making adjustments (electronic adjustments,turning adjustable resistors or whatever)whatever,start to play the disc again and it started acting up. Also just because stylus is "new in box" what ever that's no gaurantee. John at cedatum told me some years back he bought a case of 100 new old stock carts and only 1 worked as it should.The other 99 allo needed repair. That's why I feel kind of sorry for all the people that pay high dollar for new in box only to get it and find out it doesn't work. I know I got the advice about the adjustment but mine didn't need it,plus if it was working and then all of a sudden it's not,if you haven't messed with that adjustment I'd say that's not the problem,just sitting there u8ntouched i can't picture the adjustment adjusting itself. Maybe if it was a player that ups just dropped on your doorstep,yeah maybe,but to work one day and the next day it starts acting up,i really doubt it's adjustment. I'd send that other cart in and let him look at that.

[jjones7]

So more on this problem.

So I finally took the top off the player and inspected that drive motor and belt. The belt is in great shape and appears to have the right tension, etc. I cleaned everything that I could get to and it appears it all looks good. However, the problem persists. I’m starting to wonder if that motor is in itself going bad or if it’s getting bad or intermittent current, or if whatever circuit board or ‘brain’ that should be telling it to track the arm across the disc smoothly is having problems. I shot some video and put it into a playlist. If anyone here has the time, could you take a look and tell me what you think:

[b]https://youtube.com/playlist?list=PLOJ1hsooBU3-R98Ce7mGksfvV96y6xx95&si=VpUR1NNZuzzYRSAk[/b]


Yeah I know the video is shaky and awful. Would you believe that I used to be a cinematographer??

From the description on the videos: There is a problem with the servo drive motor that moves the cartridge arm along the disc. The disc will play well for about a minute and then the drive motor will push the arm forward, skipping about 15-30 seconds of the disc's play. I know that the disc and the stylus cartridge are in excellent shape, and the main belt for the platter appears to be in good shape. This video shows the malfunction. The belt appears to be in excellent shape and in the proper place.

[ketonic_dude]

I didn't realize this was a new stylus, it could just be the tension on your stylus is to too light and the needle is jumping around. From what John Greves has said you can adjust the tension by pressing down on the fly lead right at the tip of the metal ball that connects the stylus to the player. Now you want to be real tender when you do this and John said if there is any corrosion on the fly lead it will most likely break. So I'd recommend this only as a last resort. I have never done this adjustment myself so I don't know what to expect but John said he's revived styli that he thought was dead. So maybe there is something to this. Adjust at your own risk.

[jjones7]

Well I could try the tension on the stylus but this is happening with 3 different styli, all of which worked fine before this issue started when I played the scratched up disc.

I reckon as a last resort I can bring the player (and my parts player of the same model) to 2024's CED Workshop and see if any of you Jedi-level videodisc collectors could help out this lowly videodisc apprentice!!

[jsdspif]

it has been quite some time since I worked on my sgt250 and that's what I use for my player,but doesn't that motor only turn every 10 seconds or something ,normally? I can't remember? But get a service manual for any G series player because what your dealing with is applicable to all G series. There are many troubleshooting tips in there and you may find an answer there. It may be on this site somewhere or just google for sgt100 service manual sgt 200,sgt 250 etc. Find a free one because they're there. I have one but don't know which ones I have or where I got them. I've only paid for one service manual because I couldn't find it free that was for sft 100 I think. but try getting a service manual,they are good,very detailed,very helpful and you may find the problem

[jjones7]

So maybe that's the normal motion for that motor and wheel? Now that's darned interesting. It does, however, cause the playback to skip when it does move like that after a minute or so. I'll try to get some video of the TV screen as it's playing back so you can see what that looks like. it seems like the skipping of the video happens at the same time as the motor does that. The video will play beautifully for about a minute and then it skips, almost as if it's 'caught' in a groove and then the motor does that spinning, and it gets it out of that skipping.

The only thing that worries me is that it's something that's so onerous to fix that it might not be worth tearing it all down to get at it. That would bum me out!

[jjones7]

I guess another way to put it is: is this a chicken/egg problem?

Is it skipping for some other reason and this motion of the motor is trying to correct it?

Or is the motion of the motor/wheel/belt causing the skipping?