CED VideoDisc and Player Discussion

[jeff7624]

I just purchased a SFT100W and have had a couple issues with it that I need some advice on. When I got it the stylus was defective so first thing I did was to send it to CEDatum for repairs which they are doing now. I have a second one that is supposedly NOS and does display a pretty decent picture but no sound. I looked over all the connections and cleaned the contacts for the actual stylus all to no avail. I will not have the rebuilt stylus back for a week or so seeing as I just sent it out but I wanted to pick some brains to see if a bad stylus could provide a picture but no sound. From everything I have looked at it seems as it probably involves the electronics but before I begin to tear into that i figured I would check. According to the seller it had sound and picture before he shipped it but it does not now. I have tired several discs and they all produce a good picture but no sound. I doubt it is the connection to the TV I am using as I have a VCR that connects via coax and works. Any ideas would be awesome! I am pretty handy with electronics but this thing is almost a decade older than I am so some of the mechanical stuff is kinda foreign to me. Thanks in advance for the help!

[blindfury420]

Hi Jeff! Welcome to ced magic!

I have never had a stylus display video and no audio or vice versa. If you are getting picture and no sound it is likely the mono audio demodulator that went bad. Cedatum has the part and can fix if you didn't want to! If you have a manual or if someone wants to show you the chart for voltages you could start checkin the audio ic's voltages. If they are wrong it is broke!
_________________
I dont own

McMicheal 5001h
Hitachi VIP202P
JCP 686-5705
RCA SKT265, SKT300
RCA SJT400X, SJT425

[jeff7624]

hi blindfury420! Thanks for the welcome and the quick and helpful response. I think I will end up adding the IC to my order too, replacing it is no issue for me. Heck at least it is pretty cheap, and short of no sound this player works great. I was honestly surprised that a movie could be recorded onto a disc like and actually get a really good picture. Saw an article on these machines and decided to grab one. Goes along perfect with my Atari 2600, Commodore 64 and 128 and my NES. Kinda fun seeing as all of these are older than I am haha

[blindfury420]

No prob Jeff! It is kinda weird havin electronics older than yourself right? hahah. When you add the part to your list go ahead and ask cedatum if they agree. I am sure they will and have no problem sending you the part. Do you by chance have a frequency counter? Sometimes when you install an ic you have to adjust it, sometimes you get lucky and don't! Very rare but has happened for me!
_________________
I dont own

McMicheal 5001h
Hitachi VIP202P
JCP 686-5705
RCA SKT265, SKT300
RCA SJT400X, SJT425

[jeff7624]

I already emailed him and think that replacing the belts will be on the short list too. I don't have a frequency counter but I can get a my hands on one at school so thats no biggie. Hopefully I won't need to mess with it but if need be I have the resources luckily!

[blindfury420]

Very nice! The fc should be a 7 digit one. If I were you, I would leave the belts alone unless they really need it. The servo belt on the sft-100 is a bitch and is getting worse so if it works leave it on haha!!! If you need a picture or anything from the manual let me know.
_________________
I dont own

McMicheal 5001h
Hitachi VIP202P
JCP 686-5705
RCA SKT265, SKT300
RCA SJT400X, SJT425

[SelectaVision420]

good call on making the sft-100 your first purchase it is a fairly simple machine, a few of us here including myself have service literature for these machines, so we'll try to help out the best we can! where are you located?
_________________
(2)Sears 274 & 934(80150,10&11350), sft100, sgt250, sjt 090-400, vp550, VDR3000, VP2000 & 4000
complete '84 Dimensia Owner

[jeff7624]

Thanks for the comment SelectaVision420 I may have to take you up on the offer of schematics! I am actually in Columbus Ohio currently going to college at Ohio State. The SFT100 does seem like a pretty simple machine and for the most part I have figured out the inner workings just by observing it. Like I said the mechanical aspect is something new to me. I am familiar with how a VCR works and how a turntable works, combine the 2 and it's something totally unique. Looks like the turntable belt is about shot but the servo one is new looking and works fine so I will leave that alone. Going to order the IC chip as it seems to not be passing any signals and replace the belt which I assume should make it like new. The picture is pretty good although I do see some shaking which I assume to be the slipping belt. Hopefully the FM demodulator IC is the only one dead, it seems to be but with 30 year old electronics who knows 100%. I just can't wait until the parts arrive and I can get some sound on this thing. I have about 30 movies I am itching to try!

[jeff7624]

Interesting question that I just thought of. When I replaced my stylus with a spare I noticed a small magnet stuck in the old stylus stuck to the arm. I set it aside and put the new stylus in and attempted to play a disc. It skipped and played too fast. Found the magnet fit into the rear connector on the back of the stylus and then I got picture but no sound. First is this magnet suppose to go in the connector on the rear of the stylus and second would me playing a disc without that magnet have damaged something that would cause the no sound issue I have? It looks like the actual IC is dead but I want to make sure that this magnet won't cause any issues in the future.

[blindfury420]

The magnet connects to what I think is called the arm stretcher coil, at least it is called that on the sjt and skt model rca players. I can look it up for you I just cant remember at the moment. What this does is balance or counter the stylus' movement up and down to keep a stable image on the tv. The magnet is there to connect the two temporarily when the stylus door is closed. You can see the coil move forward as you close the door when stylus is out! I honestly cant remember if there is a quicker way to fix it other than getting a whole new working stylus arm and replace it real fast. I don't know if gluing it back is ok Very well could be though!
_________________
I dont own

McMicheal 5001h
Hitachi VIP202P
JCP 686-5705
RCA SKT265, SKT300
RCA SJT400X, SJT425

[jeff7624]

Thanks for the reply, a picture would be awesome if you have the access to one. Just to make sure I am clear in what I am describing this magnet is on the end opposite of the stylus tip. I was able to get it to stick in the little plunger thing on the tone arm I just wanted to make sure that it was something that belonged there and not something that just got into the player from some other source. Without it there was a lot of skipping, seems to play fine now with it back in other than no sound.

[blindfury420]

Yeah I can take a picture at some point tomorrow so you can match it up. It might be ok to glue that magnet back in but I have never done so I cant say that with confidence The magnet for sure belongs in the metal looking plunger, it should not be attached in any way to the stylus end with the metal plate and rubber X mount/dampeners.
I can definitely see it making skip like crazy as there
is nothing to keep the stylus tip in check when the magnet is not there to help the coil stabilize it.
_________________
I dont own

McMicheal 5001h
Hitachi VIP202P
JCP 686-5705
RCA SKT265, SKT300
RCA SJT400X, SJT425

[jeff7624]

I just wanted to thank everyone that helped me with suggestions on repairing my first CED player. Got my rebuilt stylus, a new belt and the audio IC from John@ CEDatum yesterday (amazing turnaround time and service) stuffed all the parts in and it works! I couldn't have done it without the help from everyone on here so thank you! One good thing about being obsessed with vintage electronics like this is at least they are somewhat cheap! Could have worse vices I think!