That's great news, well done 
Lens cleaning discs have a strip of fine bristles... so you can probably guess what I'm going to say about those. Avoid ! All they can do is brush dirt to the lens edge (which has a lip to prevent the lens getting scratched if the servo throws a wobbler and fires the lens at the spining disc). Cotton bud and lens cleaning solution is the only way to go.
Lens cleaning discs have a strip of fine bristles... so you can probably guess what I'm going to say about those. Avoid ! All they can do is brush dirt to the lens edge (which has a lip to prevent the lens getting scratched if the servo throws a wobbler and fires the lens at the spining disc). Cotton bud and lens cleaning solution is the only way to go.
Awesome job Mooly Dry joints seem a problem sometimes, i had a few on my Technics SU-V8X amp, she ran super warm on one side, and touch of of suspect solder joints is working like a charm.
I picked up a cheap Sony CDP-291 for $8. Works like a charm, and is great to play on the hot humid days when I dont want to use my other CD players. It has a KSS240A mechanism. However, sometimes i got problems where a disc loads and i cant press play and it doesnt play, shut it off, and refire and its good, haha its a crazy machine
Dry joints seem a problem sometimes, i had a few on my Technics SU-V8X amp, she ran super warm on one side, and touch of of suspect solder joints is working like a charm.I picked up a cheap Sony CDP-291 for $8. Works like a charm, and is great to play on the hot humid days when I dont want to use my other CD players. It has a KSS240A mechanism. However, sometimes i got problems where a disc loads and i cant press play and it doesnt play, shut it off, and refire and its good, haha its a crazy machine
You can tweak it by ear, but oscilloscope is better.
Cut a triangular tapered piece of matte black insulating tape...3mm wide tapering down to zero across the width of the tape.
Blacken the tape with a 'Nikko/Sharpie' type pen before cutting the triangular section...stick a short length of tape onto a flat substrate and cut with a razor knife.
Stick the tape in the mid part of the disc with the point of the tape facing toward the centre of the CD disc.
Play the disc and adjust focus gain until the lens noticeably emits audible noise, then back off a little until a 'gentler' and quieter sound is heard.
Ditto the tracking gain control.
Advance through the tracks until tracking across the black tape area.
Adjust EF balance such that the player will track through the tape without skipping forward or backward.
Dan.
Cut a triangular tapered piece of matte black insulating tape...3mm wide tapering down to zero across the width of the tape.
Blacken the tape with a 'Nikko/Sharpie' type pen before cutting the triangular section...stick a short length of tape onto a flat substrate and cut with a razor knife.
Stick the tape in the mid part of the disc with the point of the tape facing toward the centre of the CD disc.
Play the disc and adjust focus gain until the lens noticeably emits audible noise, then back off a little until a 'gentler' and quieter sound is heard.
Ditto the tracking gain control.
Advance through the tracks until tracking across the black tape area.
Adjust EF balance such that the player will track through the tape without skipping forward or backward.
Dan.
Last edited:
not sure how to ask this, so i'll rumble along and hope a coherent question appears at some point.
i have a couple of decent onkyo integra cdps: DX-6800 and DX-706. no problematic symptoms of any kind, although the DX-706 got a spindle motor replacement a several years ago that fixed a skipping problem.
last night, i tried playing a CD-R that i made (on a nice plextor drive on a desktop PC) over 5 years ago and neither machine would play it, although both could read the TOC. This same disc played just fine on the DX-706 least 2 years ago (last time i played the disc and the DX-6800 has been out of the usage rotation for at least 8 years). However, this same disc plays fine on a Sony CDP-X779ES. (yeah, yeah, i know; a totally different class of mechanics). so, i got curious and pulled out some other CD-Rs made around the same time frame and got the same results. All machines play regular pressed CDs perfectly. i'll open the onkyo's and clean the optics, then i guess i'll check to see how the eye pattern looks and decide where to go from there. i can't think it likely that both onkyo lasers would curiously weaken the same amount in the same amount of time considering the drastically different playback hours (DX-706 has been very heavily used for many years; DX-6800 has been touched maybe twice a year for the last 8 years, although it is the older machine). I also need to find some very recently made CD-Rs to see if they can be read by either machine.
In the meantime, any other ideas ?
Mooly?? stephensank??
Could this be the dreaded "CD Rot" of legend?
mlloyd1
i have a couple of decent onkyo integra cdps: DX-6800 and DX-706. no problematic symptoms of any kind, although the DX-706 got a spindle motor replacement a several years ago that fixed a skipping problem.
last night, i tried playing a CD-R that i made (on a nice plextor drive on a desktop PC) over 5 years ago and neither machine would play it, although both could read the TOC. This same disc played just fine on the DX-706 least 2 years ago (last time i played the disc and the DX-6800 has been out of the usage rotation for at least 8 years). However, this same disc plays fine on a Sony CDP-X779ES. (yeah, yeah, i know; a totally different class of mechanics
). so, i got curious and pulled out some other CD-Rs made around the same time frame and got the same results. All machines play regular pressed CDs perfectly. i'll open the onkyo's and clean the optics, then i guess i'll check to see how the eye pattern looks and decide where to go from there. i can't think it likely that both onkyo lasers would curiously weaken the same amount in the same amount of time considering the drastically different playback hours (DX-706 has been very heavily used for many years; DX-6800 has been touched maybe twice a year for the last 8 years, although it is the older machine). I also need to find some very recently made CD-Rs to see if they can be read by either machine. In the meantime, any other ideas ?
Mooly?? stephensank??
Could this be the dreaded "CD Rot" of legend?
mlloyd1
Last edited:
CDRs have limited lifetime, with better quality types (TDK, Verbatim etc) lasting longer.
Two dollar shop CDRs are hopeless.
/wiki/Optical_media_preservation
who-makes-absolute-best-quality-cd-r-media-data-archival-134044/
Dan.
Two dollar shop CDRs are hopeless.
archive quality cdr
/wiki/Optical_media_preservation
who-makes-absolute-best-quality-cd-r-media-data-archival-134044/
Dan.
Worth looking at the RF on a scope. I found that discs burned at the highest speeds were far better (looking at the RF on playback) than burning at slow speeds. That goes against much you will hear but I found it so.
Not had a problem with any CDR's to date (dating from 2006) but all are kept cool and dark.
Not had a problem with any CDR's to date (dating from 2006) but all are kept cool and dark.
as I know the KSS210A was the replacement for the KSS-150A. The KSS-212A was mostly to find in ghetto-blasters and cheap hifi systems. Unfortunately there are no data sheets from all this laser units as known from the KSS-213C. Thus the actually different between KSS212A and KSS210A remains unknown.
Who knows more about the differences?
Currently I need a KSS-240A. There are a lot of suppliers, but from where I get NOS versions and no china copies? As I know the original manufacturer in license of SONY was Koshin, the Sony supplier for optical devices.
Thanks for advices.
I think these are listed as being of German origin... that is what it implies anyway. Look down the page. Yet they are also listed as 'unbranded'. Reputable company though, part of Farnell.
KSS240A - UNBRANDED - CD OPTICAL PICK UP KSS240A | CPC UK
KSS240A - UNBRANDED - CD OPTICAL PICK UP KSS240A | CPC UK
I don't think Sony produces KSS240 anymore. The best Kss240 is the one with 24pins IC on the bottom , like this http://mastech.com.pl/aukcje/kss240A2.jpg
The piece with 10pins IC on the bottom is harder to adjust and its life is shorter.
The piece with 10pins IC on the bottom is harder to adjust and its life is shorter.
Hi Mooly,
Excellent restoration. That machine had more of it's share of problems.
Those three controls on a KSS-240A head should never be adjusted -ever! Except (there are always exceptions) by an above average technician. The E-F balance is especially touchy, more so than you noted for the average technician.
The focus offset will change depending on age (a bit), but mostly by disc table height, which is another critical adjustment. If the head is tired, the disc motor is normally toast. The random button is the leading killer of disc motors. Many times the prime issue with malfunctioning CD players is the disc motor. Again, the disc table height setting is very critical and anything well out from the original control position simply won't track as well as if the table height was correct. Don't bother using old motors from another donor machine.
All those solder connections on heavier parts tend to have cracked solder joints, and parts that run hot often has solder pulling away from the leads. They tend to look frosty or crumbly, by looking closely from above using a magnifying glass you can sometimes see a dark ring around in the solder. You caught all those nicely.
To service a CD player you do require a good (usually) analog scope. DSOs that show a good eye pattern are normally very expensive. The new Rigols seem to do this okay. Some servo gains are set through a filter and oscillator using a specific test disc. Those really good techs each have their own method that works for them, but the average person can't just copy their technique. There are lot's of other clues that techs process in their heads without thinking of it, and it takes some skill and experience.
Eye patterns and all other wave forms use the X10 setting on your 'scope probe. Trying to use the X1 setting can make it so the CD doesn't even play (capacitance of the probe on X1).
Anyway, restoring a CD player properly isn't a DIY proposition. Either do it right or don't. I say that because many people do it for friends and co-workers. Most will charge something. Even if it's only for parts, not knowing what you are doing can permanently damage a new head. We have people walking in with destroyed (new) laser heads that don't want to buy another 'cause they just bought one. It's not our fault that whoever was working on the machine damaged the new parts. It got bad enough that we now refuse to sell parts. They try to get warranty after they kill it. We know what the failure rate is for name-brand heads. Near zero.
So if you like the machine, get it repaired properly. If you want to hack away at something, get one that has cosmetic issues and go for it! Just don't look at the laser light from the head, that can cost your your eye sight, and it hurts I hear. Above all, be honest with a technician so the repair costs you less. They can find out customer caused problems - but they have to troubleshoot to it. Save yourself that chargeable time.
Hopefully that helps someone, -Chris
Excellent restoration. That machine had more of it's share of problems.
Those three controls on a KSS-240A head should never be adjusted -ever! Except (there are always exceptions) by an above average technician. The E-F balance is especially touchy, more so than you noted for the average technician.
The focus offset will change depending on age (a bit), but mostly by disc table height, which is another critical adjustment. If the head is tired, the disc motor is normally toast. The random button is the leading killer of disc motors. Many times the prime issue with malfunctioning CD players is the disc motor. Again, the disc table height setting is very critical and anything well out from the original control position simply won't track as well as if the table height was correct. Don't bother using old motors from another donor machine.
All those solder connections on heavier parts tend to have cracked solder joints, and parts that run hot often has solder pulling away from the leads. They tend to look frosty or crumbly, by looking closely from above using a magnifying glass you can sometimes see a dark ring around in the solder. You caught all those nicely.
To service a CD player you do require a good (usually) analog scope. DSOs that show a good eye pattern are normally very expensive. The new Rigols seem to do this okay. Some servo gains are set through a filter and oscillator using a specific test disc. Those really good techs each have their own method that works for them, but the average person can't just copy their technique. There are lot's of other clues that techs process in their heads without thinking of it, and it takes some skill and experience.
Eye patterns and all other wave forms use the X10 setting on your 'scope probe. Trying to use the X1 setting can make it so the CD doesn't even play (capacitance of the probe on X1).
Anyway, restoring a CD player properly isn't a DIY proposition. Either do it right or don't. I say that because many people do it for friends and co-workers. Most will charge something. Even if it's only for parts, not knowing what you are doing can permanently damage a new head. We have people walking in with destroyed (new) laser heads that don't want to buy another 'cause they just bought one. It's not our fault that whoever was working on the machine damaged the new parts. It got bad enough that we now refuse to sell parts. They try to get warranty after they kill it. We know what the failure rate is for name-brand heads. Near zero.
So if you like the machine, get it repaired properly. If you want to hack away at something, get one that has cosmetic issues and go for it! Just don't look at the laser light from the head, that can cost your your eye sight, and it hurts I hear. Above all, be honest with a technician so the repair costs you less. They can find out customer caused problems - but they have to troubleshoot to it. Save yourself that chargeable time.
Hopefully that helps someone, -Chris
Hi anatech, some great practical advice there. You've done this before haven't you
Having use of a good scope as anatech mentions is absolutely essential, in fact for a lot of service work I used the scope for DC voltage checks too. Why. Because it not only shows voltage reasonably accurately but it also shows any other problems such as noise and hash. Those tray micro switches are a typical case in point. A DVM would show no problem if you monitored the logic levels produced by the switches. Use the scope and you would see a burst of noise as the contacts bounce open and closed (the cause of the first fault on this player).
Having use of a good scope as anatech mentions is absolutely essential, in fact for a lot of service work I used the scope for DC voltage checks too. Why. Because it not only shows voltage reasonably accurately but it also shows any other problems such as noise and hash. Those tray micro switches are a typical case in point. A DVM would show no problem if you monitored the logic levels produced by the switches. Use the scope and you would see a burst of noise as the contacts bounce open and closed (the cause of the first fault on this player).