A member of this forum sent me a KSS-272a for to try to repair, maybe to replace the laser diode. Well, first of all, I see laser power. It was right, about 120uW. It looks that laser diode was right. So, I replaced the potentiometers, because original potentiometers are very hard to manipulate, and another thing, this potentiometeres are of 2K2, however it measures 1k9, they was out of tolerance. I replaced the electrolitic capacitor, original measures was right, but I don't confide in 90's Nichicon capacitors. Then, I tried to adjust the laser pickup. One, two afternoons trying to adjust, and nothing, it can barely read. What was happening? It looks like it find the right signal shape, but then it get lost. What can I do? I replaced the lens, and now it is ok. Why the original lens is bad? I don't know, it has a good aspect, but it does not work right. It a bit mess to adjust the lens position, but with a 8cm size CD it can be adjusted. Another problem, is that if unscrew the potentiometers board to adjust the potentiometers, the board get board stumble with the motor, and the CD can't read the TOC, a mess...
And yes, it is necesary to adjust the azimuth screws located beneath, yes, a mess...
Well, now it working. The only doubt is how to adjust TB(tracking balance), because following the service manual method don't works.
Needless to say that original laser diode was not replaced.
I still question why the lens is bad, and why it happened.
Moral: Don't blame the laser diode at first sight.
And yes, it is necesary to adjust the azimuth screws located beneath, yes, a mess...
Well, now it working. The only doubt is how to adjust TB(tracking balance), because following the service manual method don't works.
Needless to say that original laser diode was not replaced.
I still question why the lens is bad, and why it happened.
Moral: Don't blame the laser diode at first sight.
Another update. After adjusting and more and more adjusting, and RF signal perfect, and can read original CDs in bad state, but, however, it happens the following: It can't read CD-Rs.
Don't mind if the CD-R is well recorded: It can read CD-R.
However, it can read original CDs in bad state.
Something happens.
I connect all the stuff for to see the A-B-C-D-E-F diode signals, the same stuff I use for to replace and adjust a burn out laser diode.
And I see this: The signals, the sinus, are not symetrical. When I modify DC Focus Voltage its evident.
Now I'm tired. What do I'll do? I'm thinking to trasplant the Fotodiode Opic for anogher KSS-272A that I broke this same Opic. Maybe is just a little factory adjust fail, but I don't want to do more experiments.
Don't mind if the CD-R is well recorded: It can read CD-R.
However, it can read original CDs in bad state.
Something happens.
I connect all the stuff for to see the A-B-C-D-E-F diode signals, the same stuff I use for to replace and adjust a burn out laser diode.
And I see this: The signals, the sinus, are not symetrical. When I modify DC Focus Voltage its evident.
Now I'm tired. What do I'll do? I'm thinking to trasplant the Fotodiode Opic for anogher KSS-272A that I broke this same Opic. Maybe is just a little factory adjust fail, but I don't want to do more experiments.
And the pleasure of listen an old cd player that you have repaired? And there are another thing that some people does not understand, repair, try to find any explanation for a difficult fault, target the solution, and repair, is a very strong drug. Try to know how to repair some things, like cd laser pickups, is something that make me feel alive. When you know that this cd player is working thanks your knowledge, music sounds better.
In 2 afternoons one could have digitized many CD's (one often hears that that is too time consuming....) 
I don't enjoy CD's anymore since at least 15 years and never regretted anything. In fact I scrap every CD player as optical days are over because of wear-out, age, lack of spare parts and the large footprint of device and media. Of course I do know the joy of being able to repair or build stuff that is why I suggested to build an audio player. That is, of course, if the main goal is to playback music. It is just a suggestion!
I don't enjoy CD's anymore since at least 15 years and never regretted anything. In fact I scrap every CD player as optical days are over because of wear-out, age, lack of spare parts and the large footprint of device and media. Of course I do know the joy of being able to repair or build stuff that is why I suggested to build an audio player. That is, of course, if the main goal is to playback music. It is just a suggestion!
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So, should I replace the laser diode if the original is OK? I think is the best option. It don't worth to keep a used laser diode, if you have the option for replacing.
So, I started over again.
So, I started over again.
Attachments
Finally, I replaced the lens, the laser diode, I've adjusted the OPIC-Photodiode Array, and now is working flawless.
The question: Is the lens bad? Why the laser pickup was bad ajusted? It was bad adjusted at factory, or it was material fatigue?
I don't know. Now it can read all discs, CD-R, scratched discs, etc...
KSS-272A performs a bit better than KSS-151A, KSS-190A and KSS-152A.
As anecdote, when the laser pickup is in the workbench with the oscilloscopes, is very very sensitive to vibrations. Are lasers used for to detect vibrations, earthquake, etc..?
The question: Is the lens bad? Why the laser pickup was bad ajusted? It was bad adjusted at factory, or it was material fatigue?
I don't know. Now it can read all discs, CD-R, scratched discs, etc...
KSS-272A performs a bit better than KSS-151A, KSS-190A and KSS-152A.
As anecdote, when the laser pickup is in the workbench with the oscilloscopes, is very very sensitive to vibrations. Are lasers used for to detect vibrations, earthquake, etc..?
Attachments
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As I remember right, both laser diode and the plastic suspension (second image post #1) from SONY's KSS series are known for shortest life time of all exist laser units at those days.
One of the best (most reliable) Laser units I know are SANYO's SF-91 (in use in Cambridge Audio CD-4, CD-6, Trac-1 and DiscMagic/CDT - released between 1994 and 1998 - until know no faulty laser unit discover) and JVC's Optima series.
Not working CD-Player equipped with this mentioned laser units there are always other reasons present therefore than the laser diode or lens suspension (spring steel wire instead plastic).
On ebay I have found this special Dutch guy for repair service on SONY laser units from KSS-Series:
https://www.ebay.com/itm/294757258722
https://www.ebay.de/itm/294757258722
At first glance it looks very interesting to me.
Any experiences ?
One of the best (most reliable) Laser units I know are SANYO's SF-91 (in use in Cambridge Audio CD-4, CD-6, Trac-1 and DiscMagic/CDT - released between 1994 and 1998 - until know no faulty laser unit discover) and JVC's Optima series.
Not working CD-Player equipped with this mentioned laser units there are always other reasons present therefore than the laser diode or lens suspension (spring steel wire instead plastic).
On ebay I have found this special Dutch guy for repair service on SONY laser units from KSS-Series:
https://www.ebay.com/itm/294757258722
https://www.ebay.de/itm/294757258722
At first glance it looks very interesting to me.
Any experiences ?
@tiefbassuebertr and all of you readers
I am that Dutch guy who is advertising with KSS repairs on Ebay.
To start with, I don't replace laser diodes myself, I've got a technician who repairs these Sony KSS lasers for more than 3 decades
and we got an agreement that he repairs for me. He has a huge stock of original Sony laser diodes and replaces these for me.
Before everybody starts to ask if I can provide original Sony laser diodes: NO I CAN NOT.
I also do repair and modify Sony ES(D) cd-players (1988-1994) and sell them too.
For the ones interested, this is my stock at the moment (11-06-2023):
1x CDP-557ESD - new laser, Furutech IEC320, dedicated R-Core for clockboard, clockboard with SC-cut OCXO, 78xx/79xx analog section replaced with TPS7A
1x CDP-X707ES - new laser, Furutech IEC320, dedicated R-Core for clockboard, clockboard with SC-cut OCXO, 7818/7918 analog section replaced with NewClassD discrete voltageregulators. Digital psu is a Swoboda modified psu. Player has high-gloss side panels (from X779/X707 Champagne version).
1x CDP-X777ES - new laser, player is original - no mods.
1x CDP-X339ES - new laser, player is original - no mods. Original box.
1x CDP-X303ES - new laser, player is original - no mods.
My own player:
1x CDP-X7ES - new laser, Furutech IEC320, dedicated R-Core for clockboard, clockboard with SC-cut OCXO, all 78xx/79xx voltage regulators replaced with NewClassD discrete voltageregulators.
I have another CDP-337ESD and CDP-557ESD which I am working on
Keep up the good work!
Cheers and best regards,
Alex
I am that Dutch guy who is advertising with KSS repairs on Ebay.
To start with, I don't replace laser diodes myself, I've got a technician who repairs these Sony KSS lasers for more than 3 decades
and we got an agreement that he repairs for me. He has a huge stock of original Sony laser diodes and replaces these for me.
Before everybody starts to ask if I can provide original Sony laser diodes: NO I CAN NOT.
I also do repair and modify Sony ES(D) cd-players (1988-1994) and sell them too.
For the ones interested, this is my stock at the moment (11-06-2023):
1x CDP-557ESD - new laser, Furutech IEC320, dedicated R-Core for clockboard, clockboard with SC-cut OCXO, 78xx/79xx analog section replaced with TPS7A
1x CDP-X707ES - new laser, Furutech IEC320, dedicated R-Core for clockboard, clockboard with SC-cut OCXO, 7818/7918 analog section replaced with NewClassD discrete voltageregulators. Digital psu is a Swoboda modified psu. Player has high-gloss side panels (from X779/X707 Champagne version).
1x CDP-X777ES - new laser, player is original - no mods.
1x CDP-X339ES - new laser, player is original - no mods. Original box.
1x CDP-X303ES - new laser, player is original - no mods.
My own player:
1x CDP-X7ES - new laser, Furutech IEC320, dedicated R-Core for clockboard, clockboard with SC-cut OCXO, all 78xx/79xx voltage regulators replaced with NewClassD discrete voltageregulators.
I have another CDP-337ESD and CDP-557ESD which I am working on
Keep up the good work!
Cheers and best regards,
Alex
This are good news for all owner's of Sony vintage ES and DENON vintage cd players equipped with this KSS units. I will give this information several others here in Germany.@tiefbassuebertr and all of you readers
I am that Dutch guy who is advertising with KSS repairs on Ebay.
To start with, I don't replace laser diodes myself, I've got a technician who repairs these Sony KSS lasers for more than 3 decades
and we got an agreement that he repairs for me. He has a huge stock of original Sony laser diodes and replaces these for me.
Keep up the good work!
Cheers and best regards,
Alex
Some questions on your technician:
1) What is the usual life expectancy of the new laser diodes (the one from the original SONY SLD104 was the shortest from all models of laser units, that I knew) ?
2) Which other parts of these laser units also need to be replaced more often (I guess, the plastic suspension and the plastic collimator lens) ?
Thank you very much for your reply.
P.S.: My name on diyaudio is based on my early - no longer exist - website:
https://web.archive.org/web/20050213091026/http://tiefbassuebertragung.de/
The number of positions was not sufficient - the name was actually too long. As a result, he was cut off at the back. I still haven't changed it to this day, because the unique selling proposition makes it much easier for me to find my old posts.
@jean-paul ManoloMos has achieved something that goes far beyond diy-ing and is without parallel: the complete repair of laser units, with the possibility of even adjusting them more precisely. This never existed as a repair on the part of the manufacturers . Only with the Philips CDM-0 and CDM-1 was it possible to exchange the sleeve in which the diode was inserted. With some players, the diffraction grating was adjustable, but that was it. In addition, the mechanics of the early players were excellent, thanks to the high standard of precision mechanics achieved through the use of records or tape machines. Thanks to ManoloMos, such a player lasts forever. And thanks to the LP hype and thanks to streaming - which the musicians don't earn anything from - there are great used CDs available for little money - or you order them from the musicians themselves and thereby support them. Above all, ManoloMos' work makes me very happy, because while ManoloMos was tinkering, a member of this forum left me hanging. He got a BU-1 drive from me for the same purpose, a working Sony CDP-102 player as a reference and 10 Sharp LT022MC diodes. He never did anything to it and to this day has not sent any of it back. For that reason alone, it's a good feeling that thanks to ManoloMo's great CD players don't have to end up in the rubbish. Do I have time to rip? No. Only my favourite CDs for on the road.
I suspect that it is mainly due to the fact that these are purebred CD players (no CD-RW, no MP-3, no DVD-Video and no BD),Sensitive?
I just find it interesting that people spend 499 Euro to have a working laser in a 40 year old device. Plus the time for disassembly, shipping, waiting, assembly etc.
and the assumption that this promises a much higher life expectancy for Laser diode than is the case with newer devices (mainly for multinorm discs). Furthermore, high-quality DA converters are built into many vintage CD player models.
However, it must also be said that this replacement work would not have been necessary at all if Accuphase, DENON and Sony themselves had used laser units from Sanyo, Olympus or JVC (Optima series).
Unfortunately this long live laser units are only in use in a very few models - go to post #3 under
https://www.diyaudio.com/community/...ct-1-ct1-better-than-vam1254-cdpro2lf.149032/
The most used laser units unfortunately those from KSS-Series even in top class models like Sony ESPRIT, DENON and Accuphase
with a lot of deficiencies concerning parts of laser unit (plastic lens, plastic suspension, laser diode).
But if everything is done correctly when replacing the laser diode, one can assume that the service life expectancy will be significantly higher than with the laser diode from original equipment.
Life time of laser diode from original equipment was so small that e. g. the KSS-272A as a spare part was sold out the earliest of all laser unit models.
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Although FLAC = WAV but losslessly compressed.
The question is what is better? Or what is perceived as better when listening to these devices connected to a good external DAC:
- FLAC on a solid state device with enough CPU power and low jitter structure?
- WAV on a jittery 40 year old device? With new laser of course
The question is what is better? Or what is perceived as better when listening to these devices connected to a good external DAC:
- FLAC on a solid state device with enough CPU power and low jitter structure?
- WAV on a jittery 40 year old device? With new laser of course