Yes, clutching to straws is what I also do, this is why I changed those two transistors at the output off the laser current. I can try, I will check back with types, as this one is important not to mismatch.
The player does not have that a be setting. It is relatively basic as it is the second generation of Phillips players.
I have to look again at the laser bearing. It is not accessible from below, or it is but then I have to remove the whole assembly and realign it later. That would include the transfer and disk with line and angle measurement thing which I really don’t get.
What seems to be doable is to lubricate the motor shaft from above after removing the clutch that holds the disc.
And also for mixing complimentary types obviously.
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I don't want to go in all directions, it's just my experience and there is an element that we may not have addressed, it is the aging of the mylar ribbon of the laser which becomes rigid.
I have already seen the case (on a CDM4) of a ribbon becoming too rigid and which disturbed the angular momentum of the arm exactly always in the same place which also disturbed the error correction which does not seem to have a protocol for that . (Profiguy may have information on this)
I have no technical basis or measurement for this but at the time, by instinct I replaced the ribbon and it worked perfectly afterwards.
I have already seen the case (on a CDM4) of a ribbon becoming too rigid and which disturbed the angular momentum of the arm exactly always in the same place which also disturbed the error correction which does not seem to have a protocol for that . (Profiguy may have information on this)
I have no technical basis or measurement for this but at the time, by instinct I replaced the ribbon and it worked perfectly afterwards.
Hello all, I noted in reading this thread that Escherborn stated the following:
I have observed that the lower fringes of the flexprints for the laser assembly are very close to the bottom plate.
Is it possible that the flex cable is actually catching on the bottom plate? I had an issue with a Sony CD player that was skipping about midships through a disc. It turned out to be one of the flex cables catching on the chassis at the optical unit moved out. Just a thought. Glenn
I have observed that the lower fringes of the flexprints for the laser assembly are very close to the bottom plate.
Is it possible that the flex cable is actually catching on the bottom plate? I had an issue with a Sony CD player that was skipping about midships through a disc. It turned out to be one of the flex cables catching on the chassis at the optical unit moved out. Just a thought. Glenn
It skips also with the bottom removed and put on a scaffold, with the flexprint completely free
I don't think anyone really 'got it' tbh 😀
Ultimately the RF quality is the deciding factor. If its good its good.
There is no harm in doing that. Sometimes you have you to try a few things that are known to be trouble points even though they appear OK at the time. That's what I think about that transistor. Having had that fail on a few occasions it has to be worth swapping (if only to say afterwards, it still skips and wasn't going to be that anyway 🙂) Its eliminated, no doubts, you can look elsewhere.
The big problem with this fault is we still can't say for sure if its mechanical or electrical. On a traditional sled pickup you could look at the tracking error voltage and see it build up if the sled stuck. It would rise and rise and then suddenly overcome the friction and jolt forward.
The swing arm is a bit different because if the arm is still doing its 'wobble' then it has to still be free. Could it be less free? Maybe. How would that show on the tracking waveform or drive to the radial motor... I don't know.
I suppose you could monitor the voltage across the radial motor on a DVM (solder a couple of wires to get a permanent connection) and try 'the finger to stop it moving' trick and see how that affects that reading. If it looks like a reliable change you can then monitor the voltage in play and see what happens when the problem occurs. That might give a clue to a sticking radial motor.
Also monitor the output side of the radial motor drive amp on the scope looking for any change in that build up to a skipping event.
Good thinking 👍 Anything like that can cause these issues.
So I have to say you have way more patience than I do. I would have just pulled the whole mech ou of the player and swapped in another one - I have a few of these with various other issues that I save for parts, as they're the best red book transports ever made IMO. Far better than the Sony KSS stuff, but on par with the HOP M3 Sanyo (used in some Yamaha and Krell).
At this point it can't hurt to dive into the mechanics of the transport. A drop of oil in the transport bearing cant hurt, but i would blast a quick shot of compressed air in the bearing before hand - just shield the optics from any debris while doing so. A drop of light viscosity machine oil is all thats needed and gently move the arm back and forth several times.
I wouldn't bother replacing the any of the V regs. If they stay stable in output, there's no issue. Being the re capping was so long ago and no ill side effects were observed, I'd rule that out as well. You could replace the laser current amp transistor, but I doubt that is an issue either from the way it skips forward only by the same amount of time. I believe the problem is mechanical in nature, lkkely the bearing suspension or the spindle motor, which leads me to check the motor drive voltage to determine the torque capability of the motor and also the bushing wear.
At this point it can't hurt to dive into the mechanics of the transport. A drop of oil in the transport bearing cant hurt, but i would blast a quick shot of compressed air in the bearing before hand - just shield the optics from any debris while doing so. A drop of light viscosity machine oil is all thats needed and gently move the arm back and forth several times.
I wouldn't bother replacing the any of the V regs. If they stay stable in output, there's no issue. Being the re capping was so long ago and no ill side effects were observed, I'd rule that out as well. You could replace the laser current amp transistor, but I doubt that is an issue either from the way it skips forward only by the same amount of time. I believe the problem is mechanical in nature, lkkely the bearing suspension or the spindle motor, which leads me to check the motor drive voltage to determine the torque capability of the motor and also the bushing wear.
What a fantastically collaborative thread, nice one! And loads of useful information.
I’m also surprised you have not confirmed whether mechanical or electrical yet though. Where are you located @eschenborn ? I’m close to Zurich, I’ve a CD204 sitting on a shelf waiting for me to service - also intermittent skipping, but most likely the original 4 blue 33uf caps on board under mech (player heavily modified with black gates, but the known dodgy 33ufs left untouched).
cant remember how hard it is to strip the mech out, but I can do so and send it to you to try if you like?
Richard
I’m also surprised you have not confirmed whether mechanical or electrical yet though. Where are you located @eschenborn ? I’m close to Zurich, I’ve a CD204 sitting on a shelf waiting for me to service - also intermittent skipping, but most likely the original 4 blue 33uf caps on board under mech (player heavily modified with black gates, but the known dodgy 33ufs left untouched).
cant remember how hard it is to strip the mech out, but I can do so and send it to you to try if you like?
Richard
Hi Richard, that is so kind an offer! Thank you!
I am in Berlin right now.
What is your idea, I'd use your mech in order to confirm either mechanical or electrical fault? As yours also skips we'd possibly introduce new variants here. But I am open in any direction. I could at least replace your blue Philips axials 🙂
@profiguy , according to your expertise, would it be drag and drop to swap a CDM-1 against a CDM-0? I actually also have a 104 which is completely unmodified and untouched and unopened. I did not even think of swapping anything as it still works and I find this is very remarkable and somewhat precious. I was thinking to adjust it if it fails but not to modify anything. The 204 instead has been my guinea pig in the sense of "how far can I go" sound-wise, successful so far. No idea which CDM is in the 104.
The 104 sits on a place in the shelf where it takes some time to free it, but I could at least look what is inside. Lots of corroded griplets I assume 🙂
I am listening to an original Arcam Alpha with a recapped analogue section, not bad, but the 204 is better. There is a functioning Grundig 8400 MKII waiting in the restoration queue which sounds better than the Arcam, but the queue is blocked by the 204.
If you have any collaborative idea of getting your player back to snuff and mine with it, @dowser , feel free to suggest it.
I think I might change the transistor in the Laser supply according to @Mooly 's gut feeling, which I honor a lot 🙂 That then will be the last electronic straw clutched. after this, and only eventually, only mechanical tests.
I think I should be able to get to the bearings of both spindle and laser motor in order to lubricate them. I even have access to an ESD mat and a wristband. After re-reading @nanocamp 's guide to re-align the laser in the CDM-1 I think I can unscrew the lower bracket of the RAFOC without needing to do the transparent disc ceremony after re-assembly (which as every reader here will have understood by know scares the hell out of me).
@profiguy I think I am moderately patient. But the player – modified as it is – simply sounds extremely great.
I started an inventory of all my small signal transistors distributed in dozens of bags in scores of boxes in order to find a substitute for 6118, but before going on with that I'll pull out the 104 and have a look inside.
I am in Berlin right now.
What is your idea, I'd use your mech in order to confirm either mechanical or electrical fault? As yours also skips we'd possibly introduce new variants here. But I am open in any direction. I could at least replace your blue Philips axials 🙂
@profiguy , according to your expertise, would it be drag and drop to swap a CDM-1 against a CDM-0? I actually also have a 104 which is completely unmodified and untouched and unopened. I did not even think of swapping anything as it still works and I find this is very remarkable and somewhat precious. I was thinking to adjust it if it fails but not to modify anything. The 204 instead has been my guinea pig in the sense of "how far can I go" sound-wise, successful so far. No idea which CDM is in the 104.
The 104 sits on a place in the shelf where it takes some time to free it, but I could at least look what is inside. Lots of corroded griplets I assume 🙂
I am listening to an original Arcam Alpha with a recapped analogue section, not bad, but the 204 is better. There is a functioning Grundig 8400 MKII waiting in the restoration queue which sounds better than the Arcam, but the queue is blocked by the 204.
If you have any collaborative idea of getting your player back to snuff and mine with it, @dowser , feel free to suggest it.
I think I might change the transistor in the Laser supply according to @Mooly 's gut feeling, which I honor a lot 🙂 That then will be the last electronic straw clutched. after this, and only eventually, only mechanical tests.
I think I should be able to get to the bearings of both spindle and laser motor in order to lubricate them. I even have access to an ESD mat and a wristband. After re-reading @nanocamp 's guide to re-align the laser in the CDM-1 I think I can unscrew the lower bracket of the RAFOC without needing to do the transparent disc ceremony after re-assembly (which as every reader here will have understood by know scares the hell out of me).
@profiguy I think I am moderately patient. But the player – modified as it is – simply sounds extremely great.
I started an inventory of all my small signal transistors distributed in dozens of bags in scores of boxes in order to find a substitute for 6118, but before going on with that I'll pull out the 104 and have a look inside.
My idea was you’d use your board on my mech, but I’d provide my board too, as you could also replace the 4 caps (99% sure that’s cause of my skipping, classic issue) & then use it to rule out yours causing the fault if it wasn’t the mech.
But, I’m fairly sure your 104 and 204 have the same mechs, so you could use that to do the same thing - it will allow you to narrow the fault down. My money is on mechanical issue 🙂
But, I’m fairly sure your 104 and 204 have the same mechs, so you could use that to do the same thing - it will allow you to narrow the fault down. My money is on mechanical issue 🙂
Oh, I could send you the whole 204, but postage would be a bit steep. Plus mine is configured to use an external valve clock…and my only working valve clock is used with my 104…so you’d have the swap crystal and passive components to from yours to get it functional…
Let's talk about that.
We don't know if your motor unit does not also have a mechanical fault / is in need of lubricating / re-aligning.
And I don't know if it is a CDM-0 as well. It does not match plug-and-play style with the CDM-1. Some sorting of wires needed. See post above.
True - if you have the patience of a saint, I will get around to changing the 5 (not 4!) 33uF and confirm it fixes the problem - in fact this thread would motivate me to do so 🙂 I could then test it has fixed before going any further. If I ordered caps now, could even do so before I go on vacation for 2 weeks mid February 🙂
Sorry about the 104/204 similarities error. There's pictures of my 204 here; https://pinkfishmedia.net/forum/thr...ast-of-my-vintage-modified-haul-cd204.269676/ - just to confirm it's the same as yours. Oh, and this one was recapped with Oscons, not Black Gates - my bad.
Richard
Sorry about the 104/204 similarities error. There's pictures of my 204 here; https://pinkfishmedia.net/forum/thr...ast-of-my-vintage-modified-haul-cd204.269676/ - just to confirm it's the same as yours. Oh, and this one was recapped with Oscons, not Black Gates - my bad.
Richard
Great that you have been enticed to tackle this. You know where to find help if it does not stop skipping 🙂
And then we will already be two to dismantle and oil the mechanic.
I don't have the patience of a saint. I have the burning impatience of a sinner. I really want to get this machine up and running again.
I used the occasion of the little peek show into the guts of the 104 to quickly replace the two light blue radial Philips brand 22uF 35V output coupling caps with two 22uF Nichicon Muse ES bipolar (my go-to coupling cap type). Nothing else done. Lots of 33uF axials confirmed.
And then we will already be two to dismantle and oil the mechanic.
I don't have the patience of a saint. I have the burning impatience of a sinner. I really want to get this machine up and running again.
I used the occasion of the little peek show into the guts of the 104 to quickly replace the two light blue radial Philips brand 22uF 35V output coupling caps with two 22uF Nichicon Muse ES bipolar (my go-to coupling cap type). Nothing else done. Lots of 33uF axials confirmed.
Thanks for showing the pic. You do have a CDM-0. Your motor board is a different iteration however, it is on page 27ff of the CDM-0 manual.