Okay, it looks mostly normal. I am surprised it doesn't go back out, but maybe that transport / controller doesn't. Typically it needs to advance to read the TOC.
We know it does the focus search - good. It does not lock onto the disc - not good.
Did you at any time turn any control on the head itself? If you increase the laser power, you can kill the head instantly, no warning.
We know it does the focus search - good. It does not lock onto the disc - not good.
Did you at any time turn any control on the head itself? If you increase the laser power, you can kill the head instantly, no warning.
@anatech I know its really difficult working from pictures and videos but does that lens in the video when it does the focus search routine look limited in its movement. The starting point looks very low as if the suspension has sagged and it doesn't seem to rise all that much. Difficult just from a video to tell.
@anatech @Mooly if you need to help me I can provide other videos with different subject or different point of view. Or other you need.
@Mooly I've read your posts at the top of this thread, and I was hopeful to resuscitate my cd player in the same way ...
Is possible to buy anywhere a good replacement for my KSS240A ? Seems that the 10/15€ ones found on the web are fake ... is it true ?
@Mooly I've read your posts at the top of this thread, and I was hopeful to resuscitate my cd player in the same way ...
Is possible to buy anywhere a good replacement for my KSS240A ? Seems that the 10/15€ ones found on the web are fake ... is it true ?
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Fake is maybe the wrong word, they are non Sony replacements and should not be advertised as such. So I suppose 'fake' in that sense. The original Sony's went out of production a decades or more ago as far as I recall. I haven't fitted one in many many years now and wouldn't like to say what the current state of play is with replacements.
Having said that Donberg claim to have originals at a price of course.
https://www.donberg.co.uk/descript/k/kss_240a.htm
Having said that Donberg claim to have originals at a price of course.
https://www.donberg.co.uk/descript/k/kss_240a.htm
I think the biggest thing you need is a brass sleeve bearing on the head where the guide rod passes through. If it doesn't have those, do not buy them. The cheapest ones are absolute junk. I have used some others with success. Some were just garbage.
I use a laser power meter to determine if the laser works. About 0.08 mW for those. If you look down from a very high level, you may see a point of red light, very directional. Brief glimpse from very high up. You do not want to damage your eyesight. I have seen remote control check cards that glow with IR light, I don't know if the is is a safer way. I simply bought a laser power meter, and they are expensive.
I do not have the time to watch videos, sorry. If the lens motion is limited, you may be missing a supply voltage. I have not seen these sag that much to be honest, not like some of the original Philips transports.
I use a laser power meter to determine if the laser works. About 0.08 mW for those. If you look down from a very high level, you may see a point of red light, very directional. Brief glimpse from very high up. You do not want to damage your eyesight. I have seen remote control check cards that glow with IR light, I don't know if the is is a safer way. I simply bought a laser power meter, and they are expensive.
I do not have the time to watch videos, sorry. If the lens motion is limited, you may be missing a supply voltage. I have not seen these sag that much to be honest, not like some of the original Philips transports.
Ops... I found another mistake...
Months ago, the first time spindle motor won't start, I desoldered it to replace. but it wasn't the problem :-( so I re-placed the same old spindle motor.
Now, reading other infos on web (and thinking more...) I saw that the distance CD to laser have to be 2mm: is the same for all CD player?
Months ago, the first time spindle motor won't start, I desoldered it to replace. but it wasn't the problem :-( so I re-placed the same old spindle motor.
Now, reading other infos on web (and thinking more...) I saw that the distance CD to laser have to be 2mm: is the same for all CD player?
Hi elpossa,
That distance is critical. I have always cautioned people when messing with that.
They normally have a jig to the base of the turntable to the transport surface, or a jig to the bottom of the turntable. The lens to turntable top surface (bottom of the CD) will be the same for everything using that head. Normally they don't measure it that way (but it would make sense).
If this is wrong it will cause what you are seeing, and other issues. This is a critical adjustment.
Okay, so you had an issue a few months ago. What exactly did you do? Everything you may have changed. We need to know everything you touched.
This has become one of those "it has to be on my bench in front of me" things to repair. I would check all basic things first. Only once you know for certain that it is all the way it should be mechanically can you move forward. Same for electrical adjustments.
That distance is critical. I have always cautioned people when messing with that.
They normally have a jig to the base of the turntable to the transport surface, or a jig to the bottom of the turntable. The lens to turntable top surface (bottom of the CD) will be the same for everything using that head. Normally they don't measure it that way (but it would make sense).
If this is wrong it will cause what you are seeing, and other issues. This is a critical adjustment.
Okay, so you had an issue a few months ago. What exactly did you do? Everything you may have changed. We need to know everything you touched.
This has become one of those "it has to be on my bench in front of me" things to repair. I would check all basic things first. Only once you know for certain that it is all the way it should be mechanically can you move forward. Same for electrical adjustments.
Months ago: I've removed the cd support on motor spindle. Then removed the motor. This operation was unnecessary, I read later. The motor is ok, Then I refitted the motor and the cd support on the motor, without caring distance :-( :-(
I cleaned the lens with ear stick and alchool.
I don't remember, honestly, if it was working for a little bit of time after removing spindle motor.
Now I've tried to clean the lens with coffee filter and lens/screen cleaner. And tried to move trimmers: balance and focus bias.
Without results :-(
I cleaned the lens with ear stick and alchool.
I don't remember, honestly, if it was working for a little bit of time after removing spindle motor.
Now I've tried to clean the lens with coffee filter and lens/screen cleaner. And tried to move trimmers: balance and focus bias.
Without results :-(
If you hold a bit of broken CD above the lens as it does its focus search routine and if the laser/lens gets a focus lock then the spindle motor should at least give a kick as if it was going to spin the disc up to speed.
Spindle motors run at very low voltage. A good guide (and don't ask for values
) is that the ripple voltage across the motor should be minimal. If it is not then the commutator is worn/dirty. Something like that should not stop the motor spinning up to speed though.
Spindle motors run at very low voltage. A good guide (and don't ask for values
) is that the ripple voltage across the motor should be minimal. If it is not then the commutator is worn/dirty. Something like that should not stop the motor spinning up to speed though.Its all going further down the rabbit hole... the more you have altered things and the less likely it is that you will get a point where it will even attempt to read a disc.
Find another CD player with a KSS-240A, KSS-150A or KSS-210A head in it. Carefully measure the distance between the top of the disc table and top surface of the CDM. Use calipers or something accurate. Set yours to the same exact distance.
That is your starting point. Don't do anything else until you have it set correctly, and I mean nothing!!!
That is your starting point. Don't do anything else until you have it set correctly, and I mean nothing!!!
@Mooly @anatech I've tried to put a (piece if) cd took by hand above the lens... and the spindle motor start to run !
So (I think) motor is ok and laser isn't broken.
But seems that the cd support on spindle motor is too high. On my video, played 0.5x speed, the spindle motor runs when the cd is a little bit under the support. but the support is on the lower position as possible (touching the metal structure of cd mechanism).
So I think: where is the problem?
It is possible to focus the CD a little bit far by turning the trimmers? Or the problem is that the lens can't go out enough? Mooly said on #364 'The starting point looks very low as if the suspension has sagged'. Could be this the problem?
If you need I can attach the video of my test.
Andrea
So (I think) motor is ok and laser isn't broken.
But seems that the cd support on spindle motor is too high. On my video, played 0.5x speed, the spindle motor runs when the cd is a little bit under the support. but the support is on the lower position as possible (touching the metal structure of cd mechanism).
So I think: where is the problem?
It is possible to focus the CD a little bit far by turning the trimmers? Or the problem is that the lens can't go out enough? Mooly said on #364 'The starting point looks very low as if the suspension has sagged'. Could be this the problem?
If you need I can attach the video of my test.
Andrea
Hi Andrea,
Find the correct mechanical height by measuring a similar machine. This isn't like any other mechanical device. The focus must be bang on to take into account CDs with varying focal distances, and warps. It is a critical measurement.
We were issued or had to buy precise brass gauge blocks to adjust machines where you could remove the disc table. These were better than 0.1 mm tolerance. Some machines had plastic guides you could snap out (early Pioneer machines). In any event, table height was not intended to be set via trial and error. Depending on the machine you could measure the focus offset, but this may also be an electrical adjustment as well. You have to understand the machine and alignment procedure.
If the machine was in front of me on my bench I could probably get it set properly. I would either recognise the transport and select the proper gage, or have another I could use my calipers to measure. I can't do anything remotely.
Find the correct mechanical height by measuring a similar machine. This isn't like any other mechanical device. The focus must be bang on to take into account CDs with varying focal distances, and warps. It is a critical measurement.
We were issued or had to buy precise brass gauge blocks to adjust machines where you could remove the disc table. These were better than 0.1 mm tolerance. Some machines had plastic guides you could snap out (early Pioneer machines). In any event, table height was not intended to be set via trial and error. Depending on the machine you could measure the focus offset, but this may also be an electrical adjustment as well. You have to understand the machine and alignment procedure.
If the machine was in front of me on my bench I could probably get it set properly. I would either recognise the transport and select the proper gage, or have another I could use my calipers to measure. I can't do anything remotely.
Its an old trick which is why I mentioned it and it does show at a basic level that the laser is emitting and that it found a focus lock... and that the motor basically spins up with no weight or load on it.
As Anatech mentions, platter height is important and also it is important that the the disc is as actually mechanically free to spin. You could look at the voltage across the motor next (tag a couple of wires to it) and see if any voltage appears during focus search with a disc in the tray. If it does then possibly the motor is weak or there is a mechanical issue and the disc is being held somehow such as a problem with the clamp etc.
If no voltage appears at all then it looks like the laser is not finding focus lock on a disc when it is in the tray and that is likely to be a platter height issue or maybe still an issue with the pickup. When you hold a bit of disc above the lens you can set any angle you want but when a disc is in the tray you can not.
Yes. Basic checks we do differently.
A common failure with the DC motors for sled and spindle (turntable) are dead spots where the commutator shorts. I use a power supply, resistor and an oscilloscope to confirm. The other issue is worn bearings. Running the motor at slower speeds, rotate it around the axis and listen for a light knocking.
A common failure with the DC motors for sled and spindle (turntable) are dead spots where the commutator shorts. I use a power supply, resistor and an oscilloscope to confirm. The other issue is worn bearings. Running the motor at slower speeds, rotate it around the axis and listen for a light knocking.
Hi,
now my spindle motor runs putting a cd
But does not recognize the cd :-(
I filed the base of the CD support, the side opponent of the CD. So the CD is nearest to the lens and the focus (seems) to be ok.
Unfortunally I don't have a working scope now. Maybe I have one next week.
Which is the next step(s) to do for me? What do you suggest?
PS: It's very strange that I had to bring the CD closer to the lens.
Andrea
now my spindle motor runs putting a cd
But does not recognize the cd :-(
I filed the base of the CD support, the side opponent of the CD. So the CD is nearest to the lens and the focus (seems) to be ok.
Unfortunally I don't have a working scope now. Maybe I have one next week.
Which is the next step(s) to do for me? What do you suggest?
PS: It's very strange that I had to bring the CD closer to the lens.
Andrea
Andrea, the distance is very critical. If you are out of lock range it will not read the CD. You cannot do this properly by trial and error. Period.
Find another machine that no one has messed with and measure that distance, set yours exactly the same.
You are not using logic or following good advice. I'm out of here.
Find another machine that no one has messed with and measure that distance, set yours exactly the same.
Okay, the unit worked well as designed when it was new. So therefore nothing needs to be filed or modified.
You are not using logic or following good advice. I'm out of here.
@anatech I understand what you are saying. But now the spindle motor runs, and before my modify do not.
1. If now the spindle motor runs, it means that the focus is ok (sometime). Right?
2. I do not have any other machine with the same laser :-( I've tried to search on the web for focus distance for my KSS-240A, but no results.
3. I know that it is hard for you give help without having machine in front of you. But please try to give me suggestion.
Thanks to everyone
Andrea
1. If now the spindle motor runs, it means that the focus is ok (sometime). Right?
2. I do not have any other machine with the same laser :-( I've tried to search on the web for focus distance for my KSS-240A, but no results.
3. I know that it is hard for you give help without having machine in front of you. But please try to give me suggestion.
Thanks to everyone
Andrea