I don't want to confuse you even more. But there was an old thread about the CDM-1 alignment, touching the subject of the radial servo adjustment in service mode:
https://www.diyaudio.com/community/threads/adjusting-laser-on-cdm-1.21005/
I have a gut feeling that your issue is related to the radial servo. It might not be able to keep the swing arm on track sometimes, probably it goes off its control range. In other words it is not centered. Might be worth to check.
https://www.diyaudio.com/community/threads/adjusting-laser-on-cdm-1.21005/
I have a gut feeling that your issue is related to the radial servo. It might not be able to keep the swing arm on track sometimes, probably it goes off its control range. In other words it is not centered. Might be worth to check.
Thank you. I think @profiguy provided measuring for the radial servo a bit higher above, and I should still carry out some scoping of the motor voltage. So it is in the focus, what lags is my competence to carry out the examinations.
I read the thread already (a short thread which spans two decades), but now with my deepened knowledge it makes more sense to me. This (by @Salar is indeed interesting:
"I tried 2k2 focus gain while watching the eyepattern. I wonder if the correct description for this pot would be focus / tracking gain.
Because turning it anti-clockwise, you´ll hear a ticking coming up.
Turing it clockwise would make an audible hiss louder, but I noticed no difference. The his is focus gain in Sony-Players.
Turning the pot clockwise (Focus?) will make the laser lose tracking. Turning it anti-clockwise shows loss of tracking only if a disc with defects is played.
Thus I adjusted the pot by ear, listening very close to the CDM-1.
I turned the pot until the ticking just became audible."
I know the tracking gain pot from SONY players which very directly influences playability. On the skipping SONY player that I also have (oh dear) it did not make the skipping go away, though. But that's a very minor building site.
I read the thread already (a short thread which spans two decades), but now with my deepened knowledge it makes more sense to me. This (by @Salar is indeed interesting:
"I tried 2k2 focus gain while watching the eyepattern. I wonder if the correct description for this pot would be focus / tracking gain.
Because turning it anti-clockwise, you´ll hear a ticking coming up.
Turing it clockwise would make an audible hiss louder, but I noticed no difference. The his is focus gain in Sony-Players.
Turning the pot clockwise (Focus?) will make the laser lose tracking. Turning it anti-clockwise shows loss of tracking only if a disc with defects is played.
Thus I adjusted the pot by ear, listening very close to the CDM-1.
I turned the pot until the ticking just became audible."
I know the tracking gain pot from SONY players which very directly influences playability. On the skipping SONY player that I also have (oh dear) it did not make the skipping go away, though. But that's a very minor building site.
As I'll open the player again later in order to solder in a BC639 as substitute for BC635 on the motor board, I could play with that pot (after marking it) a bit, too.
Just for kicks, as everything I do with this machine.
I am tending to think the issue is indeed mechanical wear. My player had visibly seen a lot of use before it came to me.
Anyway I am grateful to @profiguy that he disclosed that he had a stash of first-gen Philips machines, so I pulled my 104 out of the parking position. I must say, with new output caps it is a tolerable substitute for its sibling of the same litter.
Just for kicks, as everything I do with this machine.
I am tending to think the issue is indeed mechanical wear. My player had visibly seen a lot of use before it came to me.
Anyway I am grateful to @profiguy that he disclosed that he had a stash of first-gen Philips machines, so I pulled my 104 out of the parking position. I must say, with new output caps it is a tolerable substitute for its sibling of the same litter.
Btw, the scenario of my 204 skipping is that it starts ticking for some seconds, so obviously trying to correct, but then in most cases becomes overwhelmed by the error and skips. Sometimes it catches itself.
Substituting 6118 did not bring changes. Neither did turning the focus/tracking gain pot. Skipping just changed style.
So I will pursue the mechanical track and try to lubricate the two motor's bearings (radial and spindle). If I got news, I'll be back here.
Have a great Sunday, everybody.
So I will pursue the mechanical track and try to lubricate the two motor's bearings (radial and spindle). If I got news, I'll be back here.
Have a great Sunday, everybody.
Thanks for trying it. To me it had to be done if only to say it wasn't that
Focus gain is often not all that critical. To high and the pickup is noisy (hissy) and to low and its more prone to mechanical shock.
It seems logical at this point. It is a strange issue, strange because its proving difficult to even pin down whether it is electronic or mechanical. Oh well
Thank you, @Mooly .
You know what? I had some success.
Yesterday evening I put two drops of oil in the little grove around the center of the motor spindle, from top. In order to do this I removed the plastic clutch and placed the oil with a needle (a cap lead actually) into the little groove between the conical part on which the disc comes to lie and the little knob in the middle. Two drops were sucked into the groove quickly. I cleaned the remaining traces with a tissue, re-attached the clutch, and put in a disc.
Play.
One skip after 15 seconds. Another one after 35. Another and final one in track 2. No skipping for the whole disk.
How crazy is that?
It did not remain that great, however. Skipping re-occured with another disk. I then put another drop of oil into the spindle and also into the groove visible at the lower bearing of the RAFOC. I also re-adjusted the radial/tracking gain pot to the position it had been before playing with it.
I listened to music without flaws for the whole evening.
This morning my bliss did not continue however. Some skipping in the disk that had played yesterday. So I put another drop of oil or two into the motor spindle. (I think I also need to get access to the motor axle.) I am listening to a disk right now. Nearly no skips, like one in every three tracks. Oiling the spindle immediately brought an effect. I have no idea how well the oil is distributed however. I used motor oil btw (motor bike).
So if anyone knows how I get access to the motor spindle of a CDM-0 motor, please explain to me!
For the oil to soak well into the RAFOC spindle however, this needs to be loosened from below (while gripping the bolt on top), slightly pushed out of its bearings, and lubricated. I did not yet do this.
From what I can gleam in the internet (mainly Nanocamp's comments on the CDM-1 on his business' site) I can pull out the RAFOC spindle without needing to realign the angle of the whole assembly afterwards. Needing to do this (the transparent disk thing) so far kept me from even considering it, but I believe to have understood that I can just pull out the axle without needing to realign
The CDM-1 motor spindle is far easier accessible than the one in the CDM-0 motor that I have. I unscrewed the allen screw on the bottom of the motor, loosening the nut before. Below the Allen screw there is a steel plate, probably the spindle's bearing plate from the bottom. Do I need to then pull out the whole motor in order to have access to the spindle? I don't see any other screws.
Keith Snook in his otherwise excellent little tutorial also talks about the CDM-1 motor. CDM-0 anyone?
So @dowser , do lubricate the two motor bearings first and look what that does to your player's skipping.
In my case I might even have two (or more?) issues, a mechanical overlying an electrical one. At the moment however, I am in to the fourth or fifth track since starting this post and it has not skipped. So I am definitely on a good path here.
On no place in the web I found the simple advice of "Put some drops of oil into the bearings and see if the problem becomes better, for then it's mechanical". That would have been helpful.
Once the ailments of my CD-204 hopefully cured I'll write a short go-to manual, electrical and mechanical, for a machine with CDM-0 and TDA1540 that then could conclude this thread. So others could be lead on a systematic research without scaring them with overcomplicated Philips procedures. I think a lot of great advice is already here (thanks again guys).
An important analytical bifurcation in this guide would be (as Mooly put it succinctly): Do I have an electrical problem? Do I have a mechanical problem? Do I have both?
PS: Now it just skipped half a track but played the following one flawlessly. I am nearly sure that if I can get access to both spindles in order to grease them properly I'll get rid of the problem.
PPS: Why did it play so well on a Sunday evening? That's the moment with least electrical pollution on the mains. Just a coincidence? (That's the electrical problem track again...)
You know what? I had some success.
Yesterday evening I put two drops of oil in the little grove around the center of the motor spindle, from top. In order to do this I removed the plastic clutch and placed the oil with a needle (a cap lead actually) into the little groove between the conical part on which the disc comes to lie and the little knob in the middle. Two drops were sucked into the groove quickly. I cleaned the remaining traces with a tissue, re-attached the clutch, and put in a disc.
Play.
One skip after 15 seconds. Another one after 35. Another and final one in track 2. No skipping for the whole disk.
How crazy is that?
It did not remain that great, however. Skipping re-occured with another disk. I then put another drop of oil into the spindle and also into the groove visible at the lower bearing of the RAFOC. I also re-adjusted the radial/tracking gain pot to the position it had been before playing with it.
I listened to music without flaws for the whole evening.
This morning my bliss did not continue however. Some skipping in the disk that had played yesterday. So I put another drop of oil or two into the motor spindle. (I think I also need to get access to the motor axle.) I am listening to a disk right now. Nearly no skips, like one in every three tracks. Oiling the spindle immediately brought an effect. I have no idea how well the oil is distributed however. I used motor oil btw (motor bike).
So if anyone knows how I get access to the motor spindle of a CDM-0 motor, please explain to me!
For the oil to soak well into the RAFOC spindle however, this needs to be loosened from below (while gripping the bolt on top), slightly pushed out of its bearings, and lubricated. I did not yet do this.
From what I can gleam in the internet (mainly Nanocamp's comments on the CDM-1 on his business' site) I can pull out the RAFOC spindle without needing to realign the angle of the whole assembly afterwards. Needing to do this (the transparent disk thing) so far kept me from even considering it, but I believe to have understood that I can just pull out the axle without needing to realign
The CDM-1 motor spindle is far easier accessible than the one in the CDM-0 motor that I have. I unscrewed the allen screw on the bottom of the motor, loosening the nut before. Below the Allen screw there is a steel plate, probably the spindle's bearing plate from the bottom. Do I need to then pull out the whole motor in order to have access to the spindle? I don't see any other screws.
Keith Snook in his otherwise excellent little tutorial also talks about the CDM-1 motor. CDM-0 anyone?
So @dowser , do lubricate the two motor bearings first and look what that does to your player's skipping.
In my case I might even have two (or more?) issues, a mechanical overlying an electrical one. At the moment however, I am in to the fourth or fifth track since starting this post and it has not skipped. So I am definitely on a good path here.
On no place in the web I found the simple advice of "Put some drops of oil into the bearings and see if the problem becomes better, for then it's mechanical". That would have been helpful.
Once the ailments of my CD-204 hopefully cured I'll write a short go-to manual, electrical and mechanical, for a machine with CDM-0 and TDA1540 that then could conclude this thread. So others could be lead on a systematic research without scaring them with overcomplicated Philips procedures. I think a lot of great advice is already here (thanks again guys).
An important analytical bifurcation in this guide would be (as Mooly put it succinctly): Do I have an electrical problem? Do I have a mechanical problem? Do I have both?
PS: Now it just skipped half a track but played the following one flawlessly. I am nearly sure that if I can get access to both spindles in order to grease them properly I'll get rid of the problem.
PPS: Why did it play so well on a Sunday evening? That's the moment with least electrical pollution on the mains. Just a coincidence? (That's the electrical problem track again...)
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As I am tentatively using the 204 again I realized another issue (of which I am not sure when it started):
The player stalls if told to go to the very latest tracks on a particularly long disk (over 12-15 tracks). I think it did this sometimes before when it was otherwise playing well. It can play those distant tracks but only if it goes there on its own; if I jump tracks it then hangs at the number I put it (say, 20), tries to focus it, and then just stalls with "20" in the display. I need to press "stop" to make it responsive again.
It did a bit of this already before it started to skip. Was easy to overwhelm so to speak. I was hoping that by replacing the caps on the display board last week it would stop this. But it has become more accentuated now. Maybe another track to think along for those of you who still have some patience with me.
The player stalls if told to go to the very latest tracks on a particularly long disk (over 12-15 tracks). I think it did this sometimes before when it was otherwise playing well. It can play those distant tracks but only if it goes there on its own; if I jump tracks it then hangs at the number I put it (say, 20), tries to focus it, and then just stalls with "20" in the display. I need to press "stop" to make it responsive again.
It did a bit of this already before it started to skip. Was easy to overwhelm so to speak. I was hoping that by replacing the caps on the display board last week it would stop this. But it has become more accentuated now. Maybe another track to think along for those of you who still have some patience with me.
Well stranger things have happened.
I remember we used to 'zap' small DC motors such as platter motors (more on Sony and the like) by applying around 9 v in each direction for a little while (always disconnect the motor if you try that). The idea was to clean up any debris on the commutator.
Thin bits of wire or the edge of a piece of thin plastic asre great to 'wipe' a bit of oil onto a motor shaft.
It's easy to get bamboozled by what did what and did that really improve things and so on. You just have to be logical and methodical. The trouble is when you do something and it definitely improves something but doesn't 'quite fix it'.
Keep persevering
Well, the "It did not QUITE fix it" seems a bit to be the way here so far.
I will be going to ask my specific lubrication questions in the dedicated "CD-104 tweaks" thread here. I hope that won't be too confusing, but maybe there is some more mechnical experience to collect there.
I've seen that you have been active there also lately. It's CDM service time!
I will be going to ask my specific lubrication questions in the dedicated "CD-104 tweaks" thread here. I hope that won't be too confusing, but maybe there is some more mechnical experience to collect there.
I've seen that you have been active there also lately. It's CDM service time!
I still do, but with a battery-powered drill and with a cork in which I planted a centered axis.Well stranger things have happened.
I remember we used to 'zap' small DC motors such as platter motors (more on Sony and the like) by applying around 9 v in each direction for a little while (always disconnect the motor if you try that). The idea was to clean up any debris on the commutator.
Thin bits of wire or the edge of a piece of thin plastic asre great to 'wipe' a bit of oil onto a motor shaft.
It's easy to get bamboozled by what did what and did that really improve things and so on. You just have to be logical and methodical. The trouble is when you do something and it definitely improves something but doesn't 'quite fix it'.
Keep persevering
the cork is applied directly to the plate and I turn it for a moment in one direction then in the other.
..
