CED VideoDisc and Player Discussion

[digicube]

Here are clips showing the 2 problems. What is causing it and how to fix?

https://drive.google.com/drive/folders/1vpFtKf1vVe8j5q8Hf7Et29VIEDRxDiz3?usp=share_link

[digicube]

Tried a different disc and it catch fines, so must be a disc problem. But the loud vibrations still exists.

[jsdspif]

i think there are magnets under the platter and these make up part of the direct drive motor. Maybe one of those is partially no longer stuck to the platter like it should be? At any rate lift the platter out and look underneath,or maybe a broken piece of something is under there. I once found a couple pieces of plastic bouncing around in one of my players and eventually figured out that there is a clip that holds a protective cover over the power supply and the pieces I found were pieces of that clip. It had just broken from old age.I don't remember if that was a j series or g series but it did create some sort of problem.
As for the disc not catching I don't know ,perhaps just check out everything involved. Maybe a piece of debris in that spot of the caddy so the catch isn't able to do it's "catching"?

[digicube]

Someone told me there is a screw at the bottom that lifts the platter to a certain height. Am I missing that screw? Here is a pic of the bottom.
https://drive.google.com/file/d/1ufxTrXVOU2cOvmwMzGpbELo03lm8YESL/view?usp=share_link[/img]

[jsdspif]

the screw is down inside there and it takes a small allen wrench (I think) my service manual is on my old computer so I can't look at it now. I think on this site somewhere or just google sjt 400 service manual or sjt300 service manual and get that.They are free don't pay for them. Also I think at the bottom of the turntable shaft between the adjustment screw and the bottom of the turntable shaft there is a small hardened disc,during shipping or moving the player around,like tipping on it's side or turning upside down I think that disc can get out from under the shaft and that creates problems. The service manuals for these players are beyond excellent,at least I think so. I'm no brainiac but they have helped me alot in my repairs. I'm the kind of person that if I have some instruction as to what to do I can usually do it.But get a service manual,all the Jseries are pretty much the same mechanically,i know the 400 does have some sort of stylus sweeper that activates during a pause (or something) and the lower models don't have that but most other stuff is all the same. I forget which manuals I have ,but they're easy to find. I downloaded mine for free from somewhare.

[digicube]

I downloaded the service manual. Got a picture when I replaced the stylus. I don't know what the right height for the platter tho. I got a picture but it's probably not the best quality since it requires calibration with an oscilloscope for the right height.

[jsdspif]

does it still have the "loud vibrations" as far as height with the j series if the hardened washer is in the bottom below the truntable shaft and you haven't dropped the player off the table or dropped the platter on the floor the height is probably fine.I know setting the height on the G series there is a gage that is used,i forget how exactly but I borrowed a gage from cedatum and then made a gage copying the one I borrowed. I had to do that because on g series you have to remove 2 screws to remove the platter and those screws often don't want to come loose. I had to exert so much pressure on the screws pushig down that it pushed the platter further down the shaft. With the j series I don't picture that height going out of adjustment and if your player is now playing properly it's in proper adjustment. There is what I consider a fairly wide range where the height can be. And by wide range I mean if you were to turn the height adjustment a half turn either way chances are it would have no ill effect. It seems like the gage would be different for the j series now that I think about it. For the g series it's a stylus cartridge and you put it in a player with a disc in it,this will be a junk disc or a single sided disc and you want blank side up.You then put a little rod into this special gage cartridge and the height needs to be between to marks on the gage pin and there's quite a bit of leeway one way or the other.Say if it's perfectly in the middle of the gage pin that would be considered perfect and at that point turning the adjustment screw one way or the other say half turn wouldn't have much affect on the height. For the j series I'm guessing same type of deal,a special cartridge with a pin but that's just a guess. I didn't think it would require a scope,but maybe it does on j series,but I know for sure it isn't neede on g series,at least when I adjusted mine I just used the gage.

[digicube]

No more vibrations. I thought the disc has to be at an optimal distance from the stylus but it seems it's a range of distance instead of an exact one.

[jsdspif]

exactly,there is a range there.You just put that gage pin in and look at the marks on it with just your eyes not a microscope or anything and there's no measuring involve,you just try to set the height so your inbetween the 2 marks on the pin. Sort of like checking the oil in your car,you just look at the dipstick and you want the oil to be between full and add 1 quart. Not drain the oil and see how much there is and get it within 2 drops of the perfect amount.