I have a Sony CDP-302 player
this is an old, ~1986, high end player.
It playes very well --- as long as it is tipped to and angle of 45° or
greater on either side. Not 40°, but 45°, maybe 43°. I measured it.
If I tip it from 40° to 45° it will start working. No bumping or
jarring required.

If it is flat or tipped to any angle front to back, the spindle motor
won't operate. The spindle motor circuit doesn't get any drive
signal.
I traced it back to the electronics board and something is shutting
down the generation of the signal. The problem is on the CD carriage,
because I loosened the electronics board and tipped them seperately.

The spindle motor is an open DC type. Coils are on the PC board with
the magnet attached to the bottom of the spindle. NOTHING appears to
be loose or jammed. All micro switches seem to be operating in all
positions. It worked intermittently in the flat position for a while.

It is suppose to spin the CD on insertion or power on and read the
TOC, then stop and wait for the play button. It does this only when
tipped at the proper angle.

I don't have a schematic, but what would be position sensitive to
shut
down the drive signal?

thanks

wrote in message
...
I have a Sony CDP-302 player
this is an old, ~1986, high end player.
It playes very well --- as long as it is tipped to and angle of 45° or
greater on either side. Not 40°, but 45°, maybe 43°. I measured it.
If I tip it from 40° to 45° it will start working. No bumping or
jarring required.

If it is flat or tipped to any angle front to back, the spindle motor
won't operate. The spindle motor circuit doesn't get any drive
signal.
I traced it back to the electronics board and something is shutting
down the generation of the signal. The problem is on the CD carriage,
because I loosened the electronics board and tipped them seperately.

The spindle motor is an open DC type. Coils are on the PC board with
the magnet attached to the bottom of the spindle. NOTHING appears to
be loose or jammed. All micro switches seem to be operating in all
positions. It worked intermittently in the flat position for a while.

It is suppose to spin the CD on insertion or power on and read the
TOC, then stop and wait for the play button. It does this only when
tipped at the proper angle.

I don't have a schematic, but what would be position sensitive to
shut
down the drive signal?

thanks

That type of motor normally has many connections to the stator coils, which
are a comparitively heavy assembly in themselves. I would suggest that the
first move would be to resolder all of those connections, if you can even
get at them.

Arfa

I agree with Arfa, sounds like loose solder somewhere on the wires or
on the pcb.
Sony also had problems with ribbon cables.

Sparkey

Its more likely the laser focussing circuit is off somehow, and only
actually locks onto the disc with the mechanical lean to one side.
A gentle!! adjustment of laser power, Fgain and Foffset (remembering their
original places) may help.

If however there are squeeking noises from the laser while the disc doesn't
spin then its possible you have a spindle drive problem.


"Sparkey" wrote in message
ups.com...
I agree with Arfa, sounds like loose solder somewhere on the wires or
on the pcb.
Sony also had problems with ribbon cables.

Sparkey

"Cliff Top" wrote in message
...
Its more likely the laser focussing circuit is off somehow, and only
actually locks onto the disc with the mechanical lean to one side.
A gentle!! adjustment of laser power, Fgain and Foffset (remembering their
original places) may help.

If however there are squeeking noises from the laser while the disc
doesn't
spin then its possible you have a spindle drive problem.



Sorry Cliff, but having worked on Sony CD players since they first came out,
I would absolutely dispute that your scenario is " more likely ". Focus
servos will lock a normal focus motor ( and indeed likewise the tracking
servo will do the same for the tracking motor ) at ANY angle, including
upside down. The lens, lens suspension and tracking and focus motors, do not
have enough mass to be sufficiently affected by gravity, that any such
effect is not easily compensated for by the power of these motors. I can't
remember *ever* having had a situation where focus gain and offset
adjustments have drifted on their own to any degree anyway, and still less,
have caused a problem that could be corrected by imposing a mechanical tilt
to a deck.

Also, I would absolutely advise against adjusting the laser power - not even
gently. It is NOT a valid adjustment on any Sony player, and in fact, on
very few players of any other manufacture, Pioneer being a notable
exception. Indiscriminate adjustment of laser power - even by a *tiny*
amount, can readily result in destruction of an otherwise good laser. Focus
gain and focus offset should only be adjusted with the benefit of a service
manual, and the proper equipment, or by long experience.

The comment about being able to hear the servos squealing, if you rock or
rotate the disc by hand when it's not turning under it's own steam however,
is a good pointer. If you do hear the squeal, there's a good chance that the
focus and tracking servos are locked, and the spindle motor is just not
being driven. If there is no servo squeal, then probably, the servos are not
locked, which is causing the system control to inhibit the spindle servo. I
would still be looking at the spindle motor stator connection soldering
first, and also at any connectors and wires going to the spindle motor
board.

Arfa

Hi!

Also, I would absolutely advise against adjusting the laser power - not
even
gently. It is NOT a valid adjustment on any Sony player, and in fact, on
very few players of any other manufacture, Pioneer being a notable
exception.

Okay...not that I disagree or anything like that, but why is this adjustment
provided if you're not supposed to use it when servicing the player? Why
spend the money to include such a thing? Is it for "factory setup only"?

William

"William R. Walsh" m
wrote in message news:Ul0mh.334766$1i1.84177@attbi_s72...
Okay...not that I disagree or anything like that, but why is this
adjustment
provided if you're not supposed to use it when servicing the player? Why
spend the money to include such a thing? Is it for "factory setup only"?

Lots of adjustments are critical in various electronics. What about high
voltage regulation adustments in CRT based sets. Would you just randomly
tweak it up if the pix was weak? Most LP adjustments are not going to do
much beyond shortening the life of the pickup.

Leonard

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Hi!

Lots of adjustments are critical in various electronics.

You'd get no argument from me. I know the critical nature of adjustments in
electronic devices, and even understand why some of them are not made to be
adjusted. But that's not really answering what I asked. I suppose it is
possible that I'm asking a question that only CD player manufacturers could
answer. :-)

I'm not wanting to come across as impolite. I'd simply like to know why this
is done.

William

"William R. Walsh" m
wrote in message news:jU0mh.334794$1i1.210997@attbi_s72...
Hi!

Lots of adjustments are critical in various electronics.

You'd get no argument from me. I know the critical nature of adjustments
in
electronic devices, and even understand why some of them are not made to
be
adjusted. But that's not really answering what I asked. I suppose it is
possible that I'm asking a question that only CD player manufacturers
could
answer. :-)

I'm not wanting to come across as impolite. I'd simply like to know why
this
is done.

William


Your question is not impolite, and I'm sure would not be taken as such by
anyone on here. Asking is how you find out.

The manufacturing tolerances of the optical block itself, are subject to an
amount of spread. These are compensated for when the block is manufactured,
by putting it into a test jig that sets certain conditions that should
result in a certain range of drive currents to produce a specific level of
laser diode output. The pot which sets the drive current is adjusted to
achieve what the manufacturers consider to be ideal for that particular
laser diode in that particular model of optical block. Once this setting has
been made, the pot is very firmly sealed, not just to make it vibration
proof, but to indicate that it should not be adjusted from its set position.
This is the case for almost all optical blocks. Other characteristics that
may result from mechanical tolerances of the deck that the optical block
becomes fitted to, or tolerances in the circuitry that the block has to work
with, are often provided with adjustments which are intended to be moved as
part of a servicing procedure.

Examples of these are focus offset, where the zero point of the servo is set
to match the average mechanical zero focus point, which should of course be
the mechanical resting point of the lens suspension, but may not be if the
turntable height is not set exactly correctly. Likewise, tracking offset
does the same to compensate for mechanical errors in the tangential or tilt
directions. There may also be adjustments which set the gains of the servos
to take into account spreads in the servo circuitry. However, many players
from the last 10 years or so, have no service physical adjustments at all.
With these players the chipsets used have fully electronic internal
adjustment systems.

As I said in the previous post, one notable exception to the "don't touch it
!" rule, is Pioneer players. The laser power pot is a minuscule little thing
located on the laser flexiprint, and is adjusted as part of the setup
procedure. Pioneer provide a set of testpoints in a single row on their
players, and detailed instructions in their manuals, on how to adjust the
entire pot-set, which is often a total of eight pots, and which includes the
power pot. Interestingly, Pioneer lasers very seldom fail or wear out. I
think in 30 odd years, I have only ever replaced perhaps two of the original
types ( there were several, but all pretty similar looking ) and maybe two
or three of the later ones which have a couple of tiny pots on their PCB.

Arfa

"Arfa Daily" wrote in message
...
As I said in the previous post, one notable exception to the "don't touch
it !" rule, is Pioneer players. The laser power pot is a minuscule little
thing located on the laser flexiprint, and is adjusted as part of the
setup procedure. Pioneer provide a set of testpoints in a single row on
their players, and detailed instructions in their manuals, on how to
adjust the entire pot-set, which is often a total of eight pots, and which
includes the power pot. Interestingly, Pioneer lasers very seldom fail or
wear out. I think in 30 odd years, I have only ever replaced perhaps two
of the original types ( there were several, but all pretty similar
looking ) and maybe two or three of the later ones which have a couple of
tiny pots on their PCB.

Arfa

This is an interesting point about the Pioneer pickups. Ican't recall ever
changing more than one or two myself. I worked at a store that sold tons of
Pioneer (Elite, mostly) and since then have not workde on them very much. I
can recall cleaning lots of spindle motors, but rarely, if ever changing
pickups, Is this the experience of others? What would you attribute the
difference in reliability to? Pioneer has always had very good laser
products in terms of performance. Do others percieve the reliability to
have been very good relative to their competitors as I do? Are the current
and lower end products holding up as well?

Leonard

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I have run thru the solders on the drive board and elsewhere.
The drive is fine when it runs and the "tilt" is a specific angle and
repeatable with bumping and jarring having no effect.

I am suspecting that it has something to do with the laser itself
since the fix (tilt) is so repeatable. It is definitely on the deck.
I checked out all the switches and the board on the deck removing and
replacing all connectors.

Apparently the electronics need feedback from the laser to tell it
there is a CD in the deck before it will generate the drive for the
spindle. Is this correct???

Therefore the Laser needs to see a reflection. So if the laser is
tipped, the reflection won't hit the right spot on the assy. I see
only a movement, apparently controlled by coils, that adjusted the
laser along the radius of the CD.

When it does play, I see the sled shaking back and forth as if
following the CD. Shouldn't the laser itself be moving by the coils
mentioned above. I think this deck has three lasers to control
tracking. I have no idea how this works. I only see one lens.

thanks for the responses.


On Sun, 31 Dec 2006 10:43:44 GMT, "Arfa Daily"
wrote:


wrote in message
.. .
I have a Sony CDP-302 player
this is an old, ~1986, high end player.
It playes very well --- as long as it is tipped to and angle of 45° or
greater on either side. Not 40°, but 45°, maybe 43°. I measured it.
If I tip it from 40° to 45° it will start working. No bumping or
jarring required.

If it is flat or tipped to any angle front to back, the spindle motor
won't operate. The spindle motor circuit doesn't get any drive
signal.
I traced it back to the electronics board and something is shutting
down the generation of the signal. The problem is on the CD carriage,
because I loosened the electronics board and tipped them seperately.

The spindle motor is an open DC type. Coils are on the PC board with
the magnet attached to the bottom of the spindle. NOTHING appears to
be loose or jammed. All micro switches seem to be operating in all
positions. It worked intermittently in the flat position for a while.

It is suppose to spin the CD on insertion or power on and read the
TOC, then stop and wait for the play button. It does this only when
tipped at the proper angle.

I don't have a schematic, but what would be position sensitive to
shut
down the drive signal?

thanks

That type of motor normally has many connections to the stator coils, which
are a comparitively heavy assembly in themselves. I would suggest that the
first move would be to resolder all of those connections, if you can even
get at them.

Arfa

"Leonard Caillouet" writes:

"William R. Walsh" m
wrote in message news:Ul0mh.334766$1i1.84177@attbi_s72...
Okay...not that I disagree or anything like that, but why is this
adjustment
provided if you're not supposed to use it when servicing the player? Why
spend the money to include such a thing? Is it for "factory setup only"?

Lots of adjustments are critical in various electronics. What about high
voltage regulation adustments in CRT based sets. Would you just randomly
tweak it up if the pix was weak? Most LP adjustments are not going to do
much beyond shortening the life of the pickup.

The laser power is set at the factory. Only a few components determine
the laser power and they don't really change much with age or use. The
feedback circuit maintains the laser power constant should the output
from the laser diode itself with respect to current descrease. One thing
that can affect it though is that dust, dirt, contamination on the optics
between the laser and the disc and photodiode can result in less optical power
reaching the disc and/or being reflected from the disc to the photodiode.
In this case, if the optics can't be cleaned - which is likely for some of
it - turning up the laser power is the only real option. But it's a last
resort, not a first resort! As has been stated, that's a good way to kill
a perfectly good laser.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

writes:

I have run thru the solders on the drive board and elsewhere.
The drive is fine when it runs and the "tilt" is a specific angle and
repeatable with bumping and jarring having no effect.

I am suspecting that it has something to do with the laser itself
since the fix (tilt) is so repeatable. It is definitely on the deck.
I checked out all the switches and the board on the deck removing and
replacing all connectors.

Apparently the electronics need feedback from the laser to tell it
there is a CD in the deck before it will generate the drive for the
spindle. Is this correct???

Therefore the Laser needs to see a reflection. So if the laser is
tipped, the reflection won't hit the right spot on the assy. I see
only a movement, apparently controlled by coils, that adjusted the
laser along the radius of the CD.

When it does play, I see the sled shaking back and forth as if
following the CD. Shouldn't the laser itself be moving by the coils
mentioned above. I think this deck has three lasers to control
tracking. I have no idea how this works. I only see one lens.

See the CD Player Repair guide at the site below.

The sled should not be shaking back and forth, only the lens. The sled
should just move occasionally to maintain the lens centered withint its
range.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Leonard Caillouet wrote:
"Arfa Daily" wrote in message
...
As I said in the previous post, one notable exception to the "don't
touch it !" rule, is Pioneer players. The laser power pot is a
minuscule little thing located on the laser flexiprint, and is
adjusted as part of the setup procedure. Pioneer provide a set of
testpoints in a single row on their players, and detailed
instructions in their manuals, on how to adjust the entire pot-set,
which is often a total of eight pots, and which includes the power
pot. Interestingly, Pioneer lasers very seldom fail or wear out. I
think in 30 odd years, I have only ever replaced perhaps two of the
original types ( there were several, but all pretty similar looking
) and maybe two or three of the later ones which have a couple of
tiny pots on their PCB. Arfa

This is an interesting point about the Pioneer pickups. Ican't
recall ever changing more than one or two myself. I worked at a
store that sold tons of Pioneer (Elite, mostly) and since then have
not workde on them very much. I can recall cleaning lots of spindle
motors, but rarely, if ever changing pickups, Is this the experience
of others? What would you attribute the difference in reliability
to? Pioneer has always had very good laser products in terms of
performance. Do others percieve the reliability to have been very
good relative to their competitors as I do? Are the current and
lower end products holding up as well?
Leonard

-----------------------------------------------------------------------

One reason Pioneer pickups were so reliable is that the pickup was mounted
"upside down" on many models, thus very little dust etc would settle in on
the turning mirror.
Still, even their models which played the disc label-up were very reliable
so far as pickups were concerned. Except of course for those which had the
lens fall off...

Mark Z.

SAM
Excellent info! Thanks -

This assy appears to have the Laser and photodiode array swapped
position wise - IE array is at rt angle to the lens.

But that doesn't tell me why I can start the CD in a tilted position
then lay it flat and it will play just fine till I stop it and try to
restart it.
It will only START in the tilted position, but will continue to play
in any position. It also must be tilted on power up or insertion to
read the TOC, otherwise it won't start on "PLAY" at all.
I just can't picture anything inside the laser assy that could be that
free to move and also be controlled to lock it into position so that
it would continue to play once started.
The lens assy only rotates on the plane of the CD and doesnt appear to
have movement in the "tip" position.

DOES the array need to see anything to cause it to start?
DOES it search at all by adjusting the tracking of the lens or the
array to FIND the CD?
DOES the array adjust ITSELF to provide tracking?
If so how?

thanks


On 01 Jan 2007 09:04:51 -0500, Sam Goldwasser
wrote:

writes:

I have run thru the solders on the drive board and elsewhere.
The drive is fine when it runs and the "tilt" is a specific angle and
repeatable with bumping and jarring having no effect.

I am suspecting that it has something to do with the laser itself
since the fix (tilt) is so repeatable. It is definitely on the deck.
I checked out all the switches and the board on the deck removing and
replacing all connectors.

Apparently the electronics need feedback from the laser to tell it
there is a CD in the deck before it will generate the drive for the
spindle. Is this correct???

Therefore the Laser needs to see a reflection. So if the laser is
tipped, the reflection won't hit the right spot on the assy. I see
only a movement, apparently controlled by coils, that adjusted the
laser along the radius of the CD.

When it does play, I see the sled shaking back and forth as if
following the CD. Shouldn't the laser itself be moving by the coils
mentioned above. I think this deck has three lasers to control
tracking. I have no idea how this works. I only see one lens.

See the CD Player Repair guide at the site below.

The sled should not be shaking back and forth, only the lens. The sled
should just move occasionally to maintain the lens centered withint its
range.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

"Mark D. Zacharias" wrote in message
. net...
Leonard Caillouet wrote:
"Arfa Daily" wrote in message
...
As I said in the previous post, one notable exception to the "don't
touch it !" rule, is Pioneer players. The laser power pot is a
minuscule little thing located on the laser flexiprint, and is
adjusted as part of the setup procedure. Pioneer provide a set of
testpoints in a single row on their players, and detailed
instructions in their manuals, on how to adjust the entire pot-set,
which is often a total of eight pots, and which includes the power
pot. Interestingly, Pioneer lasers very seldom fail or wear out. I
think in 30 odd years, I have only ever replaced perhaps two of the
original types ( there were several, but all pretty similar looking
) and maybe two or three of the later ones which have a couple of
tiny pots on their PCB. Arfa

This is an interesting point about the Pioneer pickups. Ican't
recall ever changing more than one or two myself. I worked at a
store that sold tons of Pioneer (Elite, mostly) and since then have
not workde on them very much. I can recall cleaning lots of spindle
motors, but rarely, if ever changing pickups, Is this the experience
of others? What would you attribute the difference in reliability
to? Pioneer has always had very good laser products in terms of
performance. Do others percieve the reliability to have been very
good relative to their competitors as I do? Are the current and
lower end products holding up as well?
Leonard

-----------------------------------------------------------------------

One reason Pioneer pickups were so reliable is that the pickup was mounted
"upside down" on many models, thus very little dust etc would settle in on
the turning mirror.
Still, even their models which played the disc label-up were very reliable
so far as pickups were concerned. Except of course for those which had the
lens fall off...

Mark Z.

Hi Mark

Have you ever managed to replace a completely missing lens, with one from a
different pickup ? I had quite an argument with someone once, who said that
it just can't be done, but I do it all the time - I should think at least 4
or 5 a year - did one just 2 weeks ago. I use a lens from a scrap KSS series
pickup. I think that the trick to getting it to work - or indeed even
replacing the 'real' lens when it's still rolling around in the bottom, is
to make sure that //every last trace// of glue is removed from both the
lens suspension, and the underside of the lens lip, and then to make certain
that the lens is refitted absolutely flat. I then refix it, by putting a
couple of tiny drops of cyanoacrylate superglue onto the tip of a tiny
flat-end jeweller's screwdy, and letting it seep into the crack by
capilliary action. Sometimes, I've found that the focus bias and offset need
to be adjusted slightly to optimise the performance back to normal, but
mostly, I've found that it just works right off, with no improvement to be
gained by adjustment. I'd be interested to know what others' experiences of
dealing with this problem are.

Arfa

"Sam Goldwasser" wrote in message
...
writes:

I have run thru the solders on the drive board and elsewhere.
The drive is fine when it runs and the "tilt" is a specific angle and
repeatable with bumping and jarring having no effect.

I am suspecting that it has something to do with the laser itself
since the fix (tilt) is so repeatable. It is definitely on the deck.
I checked out all the switches and the board on the deck removing and
replacing all connectors.

Apparently the electronics need feedback from the laser to tell it
there is a CD in the deck before it will generate the drive for the
spindle. Is this correct???

Therefore the Laser needs to see a reflection. So if the laser is
tipped, the reflection won't hit the right spot on the assy. I see
only a movement, apparently controlled by coils, that adjusted the
laser along the radius of the CD.

When it does play, I see the sled shaking back and forth as if
following the CD. Shouldn't the laser itself be moving by the coils
mentioned above. I think this deck has three lasers to control
tracking. I have no idea how this works. I only see one lens.

See the CD Player Repair guide at the site below.

The sled should not be shaking back and forth, only the lens. The sled
should just move occasionally to maintain the lens centered withint its
range.


I agree with Sam. As to whether the player needs to see a disc on the
turntable to spin it up, this depends on the unit. Some players will just go
ahead and turn on the laser, and spin up the disc, as soon as a 'laser home'
signal is detected. Some coarse speed adjustments then take place, along
with focus seek, until the spindle servo starts to see valid data coming off
the disc, whereupon, it will lock, and the rotational speed will stabilize
to the correct value. Other players will switch on the laser as soon as the
home signal is detected, and go ahead and look for a reflection from a disc.
Coarse focus search will take place at the same time, until the focus servo
locks. At this point, the drive to the spindle motor will be switched on,
and the data search will commence. Some players, if they fail to detect an
initial reflection, will pulse the spindle motor to rotate the disc some, in
case there was a jammy fingermark right above the lens, so there is no
simple answer to your question regarding the point at which the disc should
start to spin.

Whether or not the deck is on the tilt, the outgoing and returning beams,
should not hit any different place on the disc, or the pickup photodiode
array. This is the whole purpose of the tracking and focus servos. The lens
suspension is very soft, and the mass of the suspension and lens is very
small. The focus and tracking motors, which are actually like tiny
loudspeakers acting on the lens suspension in all directions, are plenty
pwerful enough to hold the lens in the right place, irrespective of gravity
acting on the pickup in any direction.

When the disc is rotating, you should be able to see the lens moving up and
down a little, as it follows the irregularities in the flatness of the disc
( don't believe the specs about disc flatness and eccentricity ... ) You may
also be able to see *slight* side to side movement of the lens if the disc
is particularly eccentric. To see these movements, you will need to be on
the last track of the disc so that the lens is at the disc edge. These are
the only movements that you should see with the disc playing normally. The
laser is moved on by another motor via a gear reduction system.
Approximately once every four to six seconds, you should see the whole laser
head move on by about one tooth. This movement should be smooth and regular,
and there should not be any overshoot. You certainly should not see any
shaking or violent movements of the lens, or pickup, in normal play. If the
problem is within the laser, then I think that it would have to be something
like a loose critical-angle mirror, that only lays in the right place with
the laser tipped, in which case, the only solution would be a replacement
laser. What laser type is fitted, as a matter of interest ? Many Sony lasers
are really quite cheap. Also, I take it that the disc is clamping correctly
to the turntable ?

Regarding your question about the three lasers. It does not have three
lasers as such. It is a single laser diode, whose output passes through a
splitter, to create three beams. The middle one of these is the one which
should be centred on the disc's spiral data track. This is accomplished by
keeping the two side beams an even distance either side of the track. To do
this, these two beams are focused onto two diodes in the pickup array. They
are called the "E" diode and "F" diode - hence the servo adjustment "E-F
balance". When the middle beam is exactly on the disc track, and the E-F
balance adjustment is set correctly, the outputs from the E and F diodes
will be equal, and there will be a null servo condition. As soon as the beam
moves off track, the E-F output will become unbalanced, and a positive or
negative servo condition will be created to correct the beam path. Focus
servo operation is likewise based on signal imbalance, but this time as a
result of the central beam being focused onto the "A", "B", "C" and "D"
diodes. When the beam is correctly in focus, it will be circular, and all
four diodes will be equally illuminated. If the beam is out of focus, an
astigmatic condition will be created, illuminating two of the diodes by a
greater degree, creating an inbalance, which drives the focus servo in the
appropriate direction to restore correct focus. Which two diodes are
illuminated more, depends on which direction the beam is out of focus. Data
output is the result of adding the outputs from these four diodes.

Not all optical blocks are 3 beam. Some are single, and use a completely
different scheme for deriving the servo information.

Arfa

I don't know if I will ever get this working right, but I sure am
learning a lot.

I'm sure this has to be looking for a reflection before it decides to
starts up the spindle.

I can't see the lens with the CD in. If I put a clear protective disc
in, nothing happens because it sees no reflection.

The unit is a CDP-302, a high end unit. The tag on the laser assy is
BU-1
119712

And from its construction, to replace it might cost the same as what I
paid for the unit new.

Since it will play in any position once started, is it possible the
focus/tracking drive isn't working till it starts and the at rest
position is causing the reflection to totally miss the target.


On Mon, 01 Jan 2007 18:18:05 GMT, "Arfa Daily"
wrote:


"Sam Goldwasser" wrote in message
...
writes:

I have run thru the solders on the drive board and elsewhere.
The drive is fine when it runs and the "tilt" is a specific angle and
repeatable with bumping and jarring having no effect.

I am suspecting that it has something to do with the laser itself
since the fix (tilt) is so repeatable. It is definitely on the deck.
I checked out all the switches and the board on the deck removing and
replacing all connectors.

Apparently the electronics need feedback from the laser to tell it
there is a CD in the deck before it will generate the drive for the
spindle. Is this correct???

Therefore the Laser needs to see a reflection. So if the laser is
tipped, the reflection won't hit the right spot on the assy. I see
only a movement, apparently controlled by coils, that adjusted the
laser along the radius of the CD.

When it does play, I see the sled shaking back and forth as if
following the CD. Shouldn't the laser itself be moving by the coils
mentioned above. I think this deck has three lasers to control
tracking. I have no idea how this works. I only see one lens.

See the CD Player Repair guide at the site below.

The sled should not be shaking back and forth, only the lens. The sled
should just move occasionally to maintain the lens centered withint its
range.


I agree with Sam. As to whether the player needs to see a disc on the
turntable to spin it up, this depends on the unit. Some players will just go
ahead and turn on the laser, and spin up the disc, as soon as a 'laser home'
signal is detected. Some coarse speed adjustments then take place, along
with focus seek, until the spindle servo starts to see valid data coming off
the disc, whereupon, it will lock, and the rotational speed will stabilize
to the correct value. Other players will switch on the laser as soon as the
home signal is detected, and go ahead and look for a reflection from a disc.
Coarse focus search will take place at the same time, until the focus servo
locks. At this point, the drive to the spindle motor will be switched on,
and the data search will commence. Some players, if they fail to detect an
initial reflection, will pulse the spindle motor to rotate the disc some, in
case there was a jammy fingermark right above the lens, so there is no
simple answer to your question regarding the point at which the disc should
start to spin.

Whether or not the deck is on the tilt, the outgoing and returning beams,
should not hit any different place on the disc, or the pickup photodiode
array. This is the whole purpose of the tracking and focus servos. The lens
suspension is very soft, and the mass of the suspension and lens is very
small. The focus and tracking motors, which are actually like tiny
loudspeakers acting on the lens suspension in all directions, are plenty
pwerful enough to hold the lens in the right place, irrespective of gravity
acting on the pickup in any direction.

When the disc is rotating, you should be able to see the lens moving up and
down a little, as it follows the irregularities in the flatness of the disc
( don't believe the specs about disc flatness and eccentricity ... ) You may
also be able to see *slight* side to side movement of the lens if the disc
is particularly eccentric. To see these movements, you will need to be on
the last track of the disc so that the lens is at the disc edge. These are
the only movements that you should see with the disc playing normally. The
laser is moved on by another motor via a gear reduction system.
Approximately once every four to six seconds, you should see the whole laser
head move on by about one tooth. This movement should be smooth and regular,
and there should not be any overshoot. You certainly should not see any
shaking or violent movements of the lens, or pickup, in normal play. If the
problem is within the laser, then I think that it would have to be something
like a loose critical-angle mirror, that only lays in the right place with
the laser tipped, in which case, the only solution would be a replacement
laser. What laser type is fitted, as a matter of interest ? Many Sony lasers
are really quite cheap. Also, I take it that the disc is clamping correctly
to the turntable ?

Regarding your question about the three lasers. It does not have three
lasers as such. It is a single laser diode, whose output passes through a
splitter, to create three beams. The middle one of these is the one which
should be centred on the disc's spiral data track. This is accomplished by
keeping the two side beams an even distance either side of the track. To do
this, these two beams are focused onto two diodes in the pickup array. They
are called the "E" diode and "F" diode - hence the servo adjustment "E-F
balance". When the middle beam is exactly on the disc track, and the E-F
balance adjustment is set correctly, the outputs from the E and F diodes
will be equal, and there will be a null servo condition. As soon as the beam
moves off track, the E-F output will become unbalanced, and a positive or
negative servo condition will be created to correct the beam path. Focus
servo operation is likewise based on signal imbalance, but this time as a
result of the central beam being focused onto the "A", "B", "C" and "D"
diodes. When the beam is correctly in focus, it will be circular, and all
four diodes will be equally illuminated. If the beam is out of focus, an
astigmatic condition will be created, illuminating two of the diodes by a
greater degree, creating an inbalance, which drives the focus servo in the
appropriate direction to restore correct focus. Which two diodes are
illuminated more, depends on which direction the beam is out of focus. Data
output is the result of adding the outputs from these four diodes.

Not all optical blocks are 3 beam. Some are single, and use a completely
different scheme for deriving the servo information.

Arfa

Arfa Daily wrote:
"Mark D. Zacharias" wrote in message
. net...
Leonard Caillouet wrote:
"Arfa Daily" wrote in message
...
As I said in the previous post, one notable exception to the "don't
touch it !" rule, is Pioneer players. The laser power pot is a
minuscule little thing located on the laser flexiprint, and is
adjusted as part of the setup procedure. Pioneer provide a set of
testpoints in a single row on their players, and detailed
instructions in their manuals, on how to adjust the entire pot-set,
which is often a total of eight pots, and which includes the power
pot. Interestingly, Pioneer lasers very seldom fail or wear out. I
think in 30 odd years, I have only ever replaced perhaps two of the
original types ( there were several, but all pretty similar looking
) and maybe two or three of the later ones which have a couple of
tiny pots on their PCB. Arfa

This is an interesting point about the Pioneer pickups. Ican't
recall ever changing more than one or two myself. I worked at a
store that sold tons of Pioneer (Elite, mostly) and since then have
not workde on them very much. I can recall cleaning lots of spindle
motors, but rarely, if ever changing pickups, Is this the
experience of others? What would you attribute the difference in
reliability to? Pioneer has always had very good laser products in
terms of performance. Do others percieve the reliability to have
been very good relative to their competitors as I do? Are the
current and lower end products holding up as well?
Leonard

-----------------------------------------------------------------------

One reason Pioneer pickups were so reliable is that the pickup was
mounted "upside down" on many models, thus very little dust etc
would settle in on the turning mirror.
Still, even their models which played the disc label-up were very
reliable so far as pickups were concerned. Except of course for
those which had the lens fall off...

Mark Z.

Hi Mark

Have you ever managed to replace a completely missing lens, with one
from a different pickup ? I had quite an argument with someone once,
who said that it just can't be done, but I do it all the time - I
should think at least 4 or 5 a year - did one just 2 weeks ago. I use
a lens from a scrap KSS series pickup. I think that the trick to
getting it to work - or indeed even replacing the 'real' lens when
it's still rolling around in the bottom, is to make sure that //every last
trace// of glue is removed from both the lens
suspension, and the underside of the lens lip, and then to make
certain that the lens is refitted absolutely flat. I then refix it,
by putting a couple of tiny drops of cyanoacrylate superglue onto the
tip of a tiny flat-end jeweller's screwdy, and letting it seep into
the crack by capilliary action. Sometimes, I've found that the focus
bias and offset need to be adjusted slightly to optimise the
performance back to normal, but mostly, I've found that it just works
right off, with no improvement to be gained by adjustment. I'd be
interested to know what others' experiences of dealing with this
problem are.
Arfa

I re-attached a lens just the other day, but have never tried using one from
another brand pickup. If I don't find the original rolling around in there,
I just consider it a lost cause.

BTW I have found that Pioneer lasers which oscillate have the lens coming
loose but hasn't fallen off yet.

I don't use superglue because of the danger of it fogging the lens.

Mark Z.

"Mark D. Zacharias" wrote in message
t...
Arfa Daily wrote:
"Mark D. Zacharias" wrote in message
. net...
Leonard Caillouet wrote:
"Arfa Daily" wrote in message
...
As I said in the previous post, one notable exception to the "don't
touch it !" rule, is Pioneer players. The laser power pot is a
minuscule little thing located on the laser flexiprint, and is
adjusted as part of the setup procedure. Pioneer provide a set of
testpoints in a single row on their players, and detailed
instructions in their manuals, on how to adjust the entire pot-set,
which is often a total of eight pots, and which includes the power
pot. Interestingly, Pioneer lasers very seldom fail or wear out. I
think in 30 odd years, I have only ever replaced perhaps two of the
original types ( there were several, but all pretty similar looking
) and maybe two or three of the later ones which have a couple of
tiny pots on their PCB. Arfa

This is an interesting point about the Pioneer pickups. Ican't
recall ever changing more than one or two myself. I worked at a
store that sold tons of Pioneer (Elite, mostly) and since then have
not workde on them very much. I can recall cleaning lots of spindle
motors, but rarely, if ever changing pickups, Is this the
experience of others? What would you attribute the difference in
reliability to? Pioneer has always had very good laser products in
terms of performance. Do others percieve the reliability to have
been very good relative to their competitors as I do? Are the
current and lower end products holding up as well?
Leonard

-----------------------------------------------------------------------

One reason Pioneer pickups were so reliable is that the pickup was
mounted "upside down" on many models, thus very little dust etc
would settle in on the turning mirror.
Still, even their models which played the disc label-up were very
reliable so far as pickups were concerned. Except of course for
those which had the lens fall off...

Mark Z.

Hi Mark

Have you ever managed to replace a completely missing lens, with one
from a different pickup ? I had quite an argument with someone once,
who said that it just can't be done, but I do it all the time - I
should think at least 4 or 5 a year - did one just 2 weeks ago. I use
a lens from a scrap KSS series pickup. I think that the trick to
getting it to work - or indeed even replacing the 'real' lens when
it's still rolling around in the bottom, is to make sure that //every
last trace// of glue is removed from both the lens
suspension, and the underside of the lens lip, and then to make
certain that the lens is refitted absolutely flat. I then refix it,
by putting a couple of tiny drops of cyanoacrylate superglue onto the
tip of a tiny flat-end jeweller's screwdy, and letting it seep into
the crack by capilliary action. Sometimes, I've found that the focus
bias and offset need to be adjusted slightly to optimise the
performance back to normal, but mostly, I've found that it just works
right off, with no improvement to be gained by adjustment. I'd be
interested to know what others' experiences of dealing with this
problem are.
Arfa

I re-attached a lens just the other day, but have never tried using one
from another brand pickup. If I don't find the original rolling around in
there, I just consider it a lost cause.

BTW I have found that Pioneer lasers which oscillate have the lens coming
loose but hasn't fallen off yet.

I don't use superglue because of the danger of it fogging the lens.

Mark Z.

Point taken on the lens fogging. It actually happened to me on one of the
first that I tried to reattach some years ago. That is why I now only use
the tiniest drop, and let it draw itself into the gap. Fuming and fogging is
then not a problem. Next time you get a missing lens, just give a Sony one a
try. If it's a lost cause already, you've got nothing further to lose !

Arfa

wrote in message
...
I don't know if I will ever get this working right, but I sure am
learning a lot.

I'm sure this has to be looking for a reflection before it decides to
starts up the spindle.

I can't see the lens with the CD in. If I put a clear protective disc
in, nothing happens because it sees no reflection.

The unit is a CDP-302, a high end unit. The tag on the laser assy is
BU-1
119712

And from its construction, to replace it might cost the same as what I
paid for the unit new.

Since it will play in any position once started, is it possible the
focus/tracking drive isn't working till it starts and the at rest
position is causing the reflection to totally miss the target.


I can only imagine that to be the case if the disc was not lying flat on the
turntable for some reason. That laser part number is not familiar to me.
I'll see if I can find some service info on this player, and see if I can
think of anything else that you could reasonably try. It's reaching the
point where you have to be starting to think that it's something obscure
rather than common. An experienced eye might just look at it, and see
immediately what the trouble is. On the other hand, sometimes faults like
this can baffle even the most experienced of us.

Arfa

writes:

SAM
Excellent info! Thanks -

This assy appears to have the Laser and photodiode array swapped
position wise - IE array is at rt angle to the lens.

But that doesn't tell me why I can start the CD in a tilted position
then lay it flat and it will play just fine till I stop it and try to
restart it.
It will only START in the tilted position, but will continue to play
in any position. It also must be tilted on power up or insertion to
read the TOC, otherwise it won't start on "PLAY" at all.
I just can't picture anything inside the laser assy that could be that
free to move and also be controlled to lock it into position so that
it would continue to play once started.
The lens assy only rotates on the plane of the CD and doesnt appear to
have movement in the "tip" position.

DOES the array need to see anything to cause it to start?

Usually needs focus lock to start spinning the disc.

DOES it search at all by adjusting the tracking of the lens or the
array to FIND the CD?

It resets to the inner stop.

DOES the array adjust ITSELF to provide tracking?
If so how?

The entire pickup moves to do tracking.

As others have noted, with this dramatic a change, it isn't likely to be
a matter of an adjustment, or a bad cable. The servos are no longer
capable of maintaining either focus or tracking lock. These are the sort
of problems where without a service manual, it's unlikely to be repairable.
A new pickup might help, but could also be an electronics problem.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Sam Goldwasser wrote:

Snip
The entire pickup moves to do tracking.


The entire pickup moves only when the tracking error reaches a certain
point, at which time the pickup is bumped a bit, and the tracking coils
re-center. Unless we're talking about an old Philips pivoting pickup with no
tracking coils...

But I'm pretty sure you knew this anyway.


Mark Z.

"Arfa Daily" writes:

wrote in message
...
I don't know if I will ever get this working right, but I sure am
learning a lot.

I'm sure this has to be looking for a reflection before it decides to
starts up the spindle.

I can't see the lens with the CD in. If I put a clear protective disc
in, nothing happens because it sees no reflection.

The unit is a CDP-302, a high end unit. The tag on the laser assy is
BU-1
119712

And from its construction, to replace it might cost the same as what I
paid for the unit new.

Since it will play in any position once started, is it possible the
focus/tracking drive isn't working till it starts and the at rest
position is causing the reflection to totally miss the target.


I can only imagine that to be the case if the disc was not lying flat on the
turntable for some reason. That laser part number is not familiar to me.
I'll see if I can find some service info on this player, and see if I can
think of anything else that you could reasonably try. It's reaching the
point where you have to be starting to think that it's something obscure
rather than common. An experienced eye might just look at it, and see
immediately what the trouble is. On the other hand, sometimes faults like
this can baffle even the most experienced of us.

I agree it may be obscure and possibly an electronic problem. There are
some differences in the part of the circuit used for the focus seach, so
your hypothesis is at least possible.

What I have done in the past to examine what's happening when it tries
to focus is to cut down a normal CD to just larger than the inner track.
One of those mini-CDs might also work. If you see the lens not moving
up and down very far, then initial focus search may be the problme.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

"Mark D. Zacharias" writes:

Sam Goldwasser wrote:

Snip
The entire pickup moves to do tracking.


The entire pickup moves only when the tracking error reaches a certain
point, at which time the pickup is bumped a bit, and the tracking coils
re-center. Unless we're talking about an old Philips pivoting pickup with no
tracking coils...

No, not those! Anything but those!

But I'm pretty sure you knew this anyway.

Right, it was in direct reponse to the original question but perhaps the
reply didn't quite make it intact. :-)

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

I re-attached a lens just the other day, but have never tried using one
from another brand pickup. If I don't find the original rolling around in
there, I just consider it a lost cause.

BTW I have found that Pioneer lasers which oscillate have the lens coming
loose but hasn't fallen off yet.

I don't use superglue because of the danger of it fogging the lens.

Mark Z.

Point taken on the lens fogging. It actually happened to me on one of the
first that I tried to reattach some years ago. That is why I now only use
the tiniest drop, and let it draw itself into the gap. Fuming and fogging is
then not a problem. Next time you get a missing lens, just give a Sony one a
try. If it's a lost cause already, you've got nothing further to lose !

Arfa

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in it.
I was thinking about trying a lens from a compact stereo CD unit I just
shredded for parts. I realize its CD vs DVD but the lens's look the
same. As observed "got nothing further to lose !"

tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in it.

blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

b wrote:
tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in it.

blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

it was "broken" when I got it. The scratches I can see from somebody
previously getting in there and fooling around. Which they did. But the
bubbles they've got me stumped. If I manage to get a picture of the lens
I'll post it.

"tomh" wrote in message news:39Amh.49$y3.6@llnews...
b wrote:
tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in it.

blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

it was "broken" when I got it. The scratches I can see from somebody
previously getting in there and fooling around. Which they did. But the
bubbles they've got me stumped. If I manage to get a picture of the lens
I'll post it.

I've seen bubbled lenses from owners trying cleaning fluids, and also from
focus or tracking drive faults, which have heated up the focus or tracking
motor coils, resulting in a melted lens. It's worth trying a lens from a
different laser ( assuming that there are no drive issues that have melted
or seized the lens suspension ). I have never cross-swapped between DVD and
CD lenses, but in principle, I don't see why there should be any fundamental
difference. For any chance of success though, note carefully what I said
about making sure that every last trace of glue is removed from the lens
mount, and the replacement lens lip, before fitting it. It is essential that
the lens is //absolutely flat// in the mount.

Arfa

"Sam Goldwasser" wrote in message
...
"Arfa Daily" writes:

wrote in message
...
I don't know if I will ever get this working right, but I sure am
learning a lot.

I'm sure this has to be looking for a reflection before it decides to
starts up the spindle.

I can't see the lens with the CD in. If I put a clear protective disc
in, nothing happens because it sees no reflection.

The unit is a CDP-302, a high end unit. The tag on the laser assy is
BU-1
119712

And from its construction, to replace it might cost the same as what I
paid for the unit new.

Since it will play in any position once started, is it possible the
focus/tracking drive isn't working till it starts and the at rest
position is causing the reflection to totally miss the target.


I can only imagine that to be the case if the disc was not lying flat on
the
turntable for some reason. That laser part number is not familiar to me.
I'll see if I can find some service info on this player, and see if I can
think of anything else that you could reasonably try. It's reaching the
point where you have to be starting to think that it's something obscure
rather than common. An experienced eye might just look at it, and see
immediately what the trouble is. On the other hand, sometimes faults like
this can baffle even the most experienced of us.

I agree it may be obscure and possibly an electronic problem. There are
some differences in the part of the circuit used for the focus seach, so
your hypothesis is at least possible.

What I have done in the past to examine what's happening when it tries
to focus is to cut down a normal CD to just larger than the inner track.
One of those mini-CDs might also work. If you see the lens not moving
up and down very far, then initial focus search may be the problme.

Long ago, I cut a large chunk out of an old CD with a hacksaw. That allowed
me to position the hole such that disc was over the lens, but the lens could
be seen through the hole. i don't know where that disc is now - buried
somewhere deep in the workshop no doubt. These days, I tend to just lift the
deck out, and just watch the lens action by looking under the disc or, if
you can remove the disc clamp to get good access to the top of the laser,
you can just hold a disc over the top of it at about turntable height, and
as parallel to the deck as you can manage. You can usually get the focus
servo to lock, and even 'play' with it by moving the disc up and down. It's
quite fascinating to watch the lens follow the disc as though it was stuck
there with invisible glue. I also have a circular magnet removed from a
scrap deck's disc clamp. this is very useful for sticking a disc down to the
turntable, after removing a disc clamp for eyeball access. You can also
BluTack a disc down at a pinch.

Having had a further think about this problem, could it be that something is
restricting the movement of the sled when the deck is flat ? Most players
will shuffle the laser off the home switch and back on again, just to make
sure that the laser is home, before turning on the laser and starting the
'disc in' initialisation procedure, ending in reading the TOC. If that
shuffle couldn't take place, or was being restricted in some way, then the
system control micro may not be getting the right switch signals to start it
off. If you can get the deck out in your hand whilst keeping it connected,
or otherwise get good visual access to it, try just opening and closing the
drawer, with no disc loaded, and watch exactly what happens - laser shuffle,
laser burning, focus seek etc, then try the same again with the deck tipped,
and see if you can see any difference in what happens. If not, try the same
with a disc loaded.

Arfa

I've tried so many things, I probably looked at that.
There is no restraint on the sled. It moves freely.
The drive belts for the table are weak, but I twisted them and it
seemed to work ok. I made sure it was fully seated when closed. It
wouldn't clamp the CD if it wasn't. I have watched it seeking track 0
but I don't remember if that was only when tipped or if it did it when
it was flat also. I believe there was no action whatever when it is
flat, but I will look again.
I can't see the lens assy from the bottom, but I will try a small CD
and see if I can view it then.

thanks.


On Wed, 03 Jan 2007 02:19:21 GMT, "Arfa Daily"
wrote:


"Sam Goldwasser" wrote in message
...
"Arfa Daily" writes:

wrote in message
...
I don't know if I will ever get this working right, but I sure am
learning a lot.

I'm sure this has to be looking for a reflection before it decides to
starts up the spindle.

I can't see the lens with the CD in. If I put a clear protective disc
in, nothing happens because it sees no reflection.

The unit is a CDP-302, a high end unit. The tag on the laser assy is
BU-1
119712

And from its construction, to replace it might cost the same as what I
paid for the unit new.

Since it will play in any position once started, is it possible the
focus/tracking drive isn't working till it starts and the at rest
position is causing the reflection to totally miss the target.


I can only imagine that to be the case if the disc was not lying flat on
the
turntable for some reason. That laser part number is not familiar to me.
I'll see if I can find some service info on this player, and see if I can
think of anything else that you could reasonably try. It's reaching the
point where you have to be starting to think that it's something obscure
rather than common. An experienced eye might just look at it, and see
immediately what the trouble is. On the other hand, sometimes faults like
this can baffle even the most experienced of us.

I agree it may be obscure and possibly an electronic problem. There are
some differences in the part of the circuit used for the focus seach, so
your hypothesis is at least possible.

What I have done in the past to examine what's happening when it tries
to focus is to cut down a normal CD to just larger than the inner track.
One of those mini-CDs might also work. If you see the lens not moving
up and down very far, then initial focus search may be the problme.

Long ago, I cut a large chunk out of an old CD with a hacksaw. That allowed
me to position the hole such that disc was over the lens, but the lens could
be seen through the hole. i don't know where that disc is now - buried
somewhere deep in the workshop no doubt. These days, I tend to just lift the
deck out, and just watch the lens action by looking under the disc or, if
you can remove the disc clamp to get good access to the top of the laser,
you can just hold a disc over the top of it at about turntable height, and
as parallel to the deck as you can manage. You can usually get the focus
servo to lock, and even 'play' with it by moving the disc up and down. It's
quite fascinating to watch the lens follow the disc as though it was stuck
there with invisible glue. I also have a circular magnet removed from a
scrap deck's disc clamp. this is very useful for sticking a disc down to the
turntable, after removing a disc clamp for eyeball access. You can also
BluTack a disc down at a pinch.

Having had a further think about this problem, could it be that something is
restricting the movement of the sled when the deck is flat ? Most players
will shuffle the laser off the home switch and back on again, just to make
sure that the laser is home, before turning on the laser and starting the
'disc in' initialisation procedure, ending in reading the TOC. If that
shuffle couldn't take place, or was being restricted in some way, then the
system control micro may not be getting the right switch signals to start it
off. If you can get the deck out in your hand whilst keeping it connected,
or otherwise get good visual access to it, try just opening and closing the
drawer, with no disc loaded, and watch exactly what happens - laser shuffle,
laser burning, focus seek etc, then try the same again with the deck tipped,
and see if you can see any difference in what happens. If not, try the same
with a disc loaded.

Arfa

wrote in message
...
I've tried so many things, I probably looked at that.
There is no restraint on the sled. It moves freely.
The drive belts for the table are weak, but I twisted them and it
seemed to work ok. I made sure it was fully seated when closed. It
wouldn't clamp the CD if it wasn't. I have watched it seeking track 0
but I don't remember if that was only when tipped or if it did it when
it was flat also. I believe there was no action whatever when it is
flat, but I will look again.
I can't see the lens assy from the bottom, but I will try a small CD
and see if I can view it then.

thanks.

Well, if the tray drive belt is weak, then the very first thing I would do
is to replace it. I wouldn't for one second believe with absolute certainty,
that the loading cycle is completing correctly and fully, just because the
disc appears to clamp. I have had similar situations many times, where the
final push of the mech, beyond just clamping the disc, works a "load
complete" switch, and that extra little bit of mechanical resistance from
the switch's spring loading, is just enough to hold it open. If, as you
suspect that you observed, the deck does absolutely nothing when it is flat,
then this would be a good indicator that the system control micro is waiting
for something like a "load complete" signal. In this situation, gravity may
well take over to assist the last little movement, when the deck is tipped.
This would also make sense with your assertion that once the deck has read
the TOC 'on the tip' as it were, it will then play in any position. The
system control micro only needs to be told that loading is complete, once.
Just change the belt, before going any further ...

Arfa

Arfa Daily wrote:
"tomh" wrote in message
news:39Amh.49$y3.6@llnews...
b wrote:
tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in
it.

blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

it was "broken" when I got it. The scratches I can see from somebody
previously getting in there and fooling around. Which they did. But
the bubbles they've got me stumped. If I manage to get a picture of
the lens I'll post it.

I've seen bubbled lenses from owners trying cleaning fluids, and also
from focus or tracking drive faults, which have heated up the focus
or tracking motor coils, resulting in a melted lens. It's worth
trying a lens from a different laser ( assuming that there are no
drive issues that have melted or seized the lens suspension ). I have
never cross-swapped between DVD and CD lenses, but in principle, I
don't see why there should be any fundamental difference. For any
chance of success though, note carefully what I said about making
sure that every last trace of glue is removed from the lens mount,
and the replacement lens lip, before fitting it. It is essential that
the lens is //absolutely flat// in the mount.
Arfa

I don't think a CD lens would EVEN work on a DVD, or vice versa. The inner
curvature of the two is different, yes? DVD's have smaller pit size.

MarkZ .

NO, I have pushed it to be sure it is all the way in.
The tip is from side to side so gravity is not at work here. A front
to back tip will not cause it to operate.

Also, it will only CONTINUE to play in any position once play is
started. If I tip it to read the TOC then lay it flat it will not
start playing.

I HAVE discovered something else.
The sled rides on 2 rails. one side has a sleeve on it, the other
rests on a roller. It will move up about 1/16 inch on that side. If I
try to start it while flat AND holding that side up it works. Once
started, I have to let it go so the sled can move and it continues to
work.
Since that is not giving me a 45° tip, it does point to the lens or
something inside being too far off to see the reflection in its normal
position. Since it comes back at a 45° tip I have to think something
inside is loose rather than the lens gimble as that only seems to move
in the plane of the CD. HOWEVER, there isn't anything else in the assy
that moves except the lens is there??????????
THEREFORE, it has to be the lens gimble, RIGHT?????????



On Wed, 03 Jan 2007 10:38:44 GMT, "Arfa Daily"
wrote:


wrote in message
.. .
I've tried so many things, I probably looked at that.
There is no restraint on the sled. It moves freely.
The drive belts for the table are weak, but I twisted them and it
seemed to work ok. I made sure it was fully seated when closed. It
wouldn't clamp the CD if it wasn't. I have watched it seeking track 0
but I don't remember if that was only when tipped or if it did it when
it was flat also. I believe there was no action whatever when it is
flat, but I will look again.
I can't see the lens assy from the bottom, but I will try a small CD
and see if I can view it then.

thanks.

Well, if the tray drive belt is weak, then the very first thing I would do
is to replace it. I wouldn't for one second believe with absolute certainty,
that the loading cycle is completing correctly and fully, just because the
disc appears to clamp. I have had similar situations many times, where the
final push of the mech, beyond just clamping the disc, works a "load
complete" switch, and that extra little bit of mechanical resistance from
the switch's spring loading, is just enough to hold it open. If, as you
suspect that you observed, the deck does absolutely nothing when it is flat,
then this would be a good indicator that the system control micro is waiting
for something like a "load complete" signal. In this situation, gravity may
well take over to assist the last little movement, when the deck is tipped.
This would also make sense with your assertion that once the deck has read
the TOC 'on the tip' as it were, it will then play in any position. The
system control micro only needs to be told that loading is complete, once.
Just change the belt, before going any further ...

Arfa

Mark D. Zacharias wrote:
Arfa Daily wrote:
"tomh" wrote in message
news:39Amh.49$y3.6@llnews...
b wrote:
tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in
it.
blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

it was "broken" when I got it. The scratches I can see from somebody
previously getting in there and fooling around. Which they did. But
the bubbles they've got me stumped. If I manage to get a picture of
the lens I'll post it.
I've seen bubbled lenses from owners trying cleaning fluids, and also
from focus or tracking drive faults, which have heated up the focus
or tracking motor coils, resulting in a melted lens. It's worth
trying a lens from a different laser ( assuming that there are no
drive issues that have melted or seized the lens suspension ). I have
never cross-swapped between DVD and CD lenses, but in principle, I
don't see why there should be any fundamental difference. For any
chance of success though, note carefully what I said about making
sure that every last trace of glue is removed from the lens mount,
and the replacement lens lip, before fitting it. It is essential that
the lens is //absolutely flat// in the mount.
Arfa

I don't think a CD lens would EVEN work on a DVD, or vice versa. The inner
curvature of the two is different, yes? DVD's have smaller pit size.

MarkZ .


yes point well taken. When I get both lens's out I'll check them
carefully. If they do show a remarkable difference I probably have a
dead DVD mechanism in my parts/junk pile that I can get a lens from.
will advise...

tomh

"Mark D. Zacharias" wrote in message
t...
Arfa Daily wrote:
"tomh" wrote in message
news:39Amh.49$y3.6@llnews...
b wrote:
tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches in
it.

blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

it was "broken" when I got it. The scratches I can see from somebody
previously getting in there and fooling around. Which they did. But
the bubbles they've got me stumped. If I manage to get a picture of
the lens I'll post it.

I've seen bubbled lenses from owners trying cleaning fluids, and also
from focus or tracking drive faults, which have heated up the focus
or tracking motor coils, resulting in a melted lens. It's worth
trying a lens from a different laser ( assuming that there are no
drive issues that have melted or seized the lens suspension ). I have
never cross-swapped between DVD and CD lenses, but in principle, I
don't see why there should be any fundamental difference. For any
chance of success though, note carefully what I said about making
sure that every last trace of glue is removed from the lens mount,
and the replacement lens lip, before fitting it. It is essential that
the lens is //absolutely flat// in the mount.
Arfa

I don't think a CD lens would EVEN work on a DVD, or vice versa. The inner
curvature of the two is different, yes? DVD's have smaller pit size.

MarkZ .
I'm not sure about the potential effects of that. Might work one way round,
but not the other. A DVD laser, for instance, will happily play a CD or
VCD.

Arfa

wrote in message
...
NO, I have pushed it to be sure it is all the way in.
The tip is from side to side so gravity is not at work here. A front
to back tip will not cause it to operate.

Also, it will only CONTINUE to play in any position once play is
started. If I tip it to read the TOC then lay it flat it will not
start playing.

I HAVE discovered something else.
The sled rides on 2 rails. one side has a sleeve on it, the other
rests on a roller. It will move up about 1/16 inch on that side. If I
try to start it while flat AND holding that side up it works. Once
started, I have to let it go so the sled can move and it continues to
work.
Since that is not giving me a 45° tip, it does point to the lens or
something inside being too far off to see the reflection in its normal
position. Since it comes back at a 45° tip I have to think something
inside is loose rather than the lens gimble as that only seems to move
in the plane of the CD. HOWEVER, there isn't anything else in the assy
that moves except the lens is there??????????
THEREFORE, it has to be the lens gimble, RIGHT?????????


Weeeeeelllllll ... Not necessarily. Firstly, just because you have manually
pushed the tray all the way in, that still doesn't say that the whole
loading process has completed correctly. There is often continued movement
to complete the loading cycle, after the tray is fully home. Sometimes, for
instance, a tray lock slides into place, finally working a switch, to tell
the micro that loading really is complete. However, leaving that aside for a
moment, I think that you can be pretty sure that a 1/16th inch of vertical
play at one of the slides, is not correct. Are you absolutely sure that
something is not broken or displaced or missing from the mech at that point
? It's not uncommon for there to be a phosphor bronze finger attached to the
laser assembly, and resting under the slide rod, to take out just the sort
of play that you are describing. If it definitely works under all
circumstances with the deck flat, but that side of the laser lifted, then
logically, that must be where your problem lies, right ?

Arfa

Well, Tipping the deck doesn't move the the sled thru any part of that
1/16 inch, unless it is tipped past 90°. So something else on the sled
is moving when it is tipped to cause it to see a reflection.
The closed drawer position, I am sure, is not the issue.
The sled doesn't move to track zero until it sees a reflection.
I can hold it there in a position that otherwise doesn't work (flat or
tipped front to back) and it still doesn't start up.
The side that is loose appears to be designed that way. There is
nothing that would hold it top AND bottom. Gravity keep the top roller
in contact with the rail. A piece as you describe would assist gravity
to hold it in just this position. There is no adj on that roller to
make it bring the sled up. There were no loose pieces in the unit.

I might be able to jury-rig this to make the roller bigger and bring
the sled up.


On Thu, 04 Jan 2007 01:15:18 GMT, "Arfa Daily"
wrote:


wrote in message
.. .
NO, I have pushed it to be sure it is all the way in.
The tip is from side to side so gravity is not at work here. A front
to back tip will not cause it to operate.

Also, it will only CONTINUE to play in any position once play is
started. If I tip it to read the TOC then lay it flat it will not
start playing.

I HAVE discovered something else.
The sled rides on 2 rails. one side has a sleeve on it, the other
rests on a roller. It will move up about 1/16 inch on that side. If I
try to start it while flat AND holding that side up it works. Once
started, I have to let it go so the sled can move and it continues to
work.
Since that is not giving me a 45° tip, it does point to the lens or
something inside being too far off to see the reflection in its normal
position. Since it comes back at a 45° tip I have to think something
inside is loose rather than the lens gimble as that only seems to move
in the plane of the CD. HOWEVER, there isn't anything else in the assy
that moves except the lens is there??????????
THEREFORE, it has to be the lens gimble, RIGHT?????????


Weeeeeelllllll ... Not necessarily. Firstly, just because you have manually
pushed the tray all the way in, that still doesn't say that the whole
loading process has completed correctly. There is often continued movement
to complete the loading cycle, after the tray is fully home. Sometimes, for
instance, a tray lock slides into place, finally working a switch, to tell
the micro that loading really is complete. However, leaving that aside for a
moment, I think that you can be pretty sure that a 1/16th inch of vertical
play at one of the slides, is not correct. Are you absolutely sure that
something is not broken or displaced or missing from the mech at that point
? It's not uncommon for there to be a phosphor bronze finger attached to the
laser assembly, and resting under the slide rod, to take out just the sort
of play that you are describing. If it definitely works under all
circumstances with the deck flat, but that side of the laser lifted, then
logically, that must be where your problem lies, right ?

Arfa

Arfa Daily wrote:
"Mark D. Zacharias" wrote in message
t...
Arfa Daily wrote:
"tomh" wrote in message
news:39Amh.49$y3.6@llnews...
b wrote:
tomh ha escrito:

Hmmm, I've got a PS2 with a lens that has bubbles and scratches
in it.

blimey, what do you do to it? set it on fire then put it out by
scraping it with a nailfile??!! ;-)

it was "broken" when I got it. The scratches I can see from
somebody previously getting in there and fooling around. Which
they did. But the bubbles they've got me stumped. If I manage to
get a picture of the lens I'll post it.

I've seen bubbled lenses from owners trying cleaning fluids, and
also from focus or tracking drive faults, which have heated up the
focus or tracking motor coils, resulting in a melted lens. It's
worth trying a lens from a different laser ( assuming that there
are no drive issues that have melted or seized the lens suspension
). I have never cross-swapped between DVD and CD lenses, but in
principle, I don't see why there should be any fundamental
difference. For any chance of success though, note carefully what I
said about making sure that every last trace of glue is removed
from the lens mount, and the replacement lens lip, before fitting
it. It is essential that the lens is //absolutely flat// in the
mount. Arfa

I don't think a CD lens would EVEN work on a DVD, or vice versa. The
inner curvature of the two is different, yes? DVD's have smaller pit
size. MarkZ .
I'm not sure about the potential effects of that. Might work one way
round, but not the other. A DVD laser, for instance, will happily
play a CD or VCD.

Arfa

That's true. Hmmm. Still, DVD players aren't optimized for CD's...

(sound effect of Markie weasling ;-)


Mark Z.

wrote in message
...
Well, Tipping the deck doesn't move the the sled thru any part of that
1/16 inch, unless it is tipped past 90°. So something else on the sled
is moving when it is tipped to cause it to see a reflection.
The closed drawer position, I am sure, is not the issue.
The sled doesn't move to track zero until it sees a reflection.
I can hold it there in a position that otherwise doesn't work (flat or
tipped front to back) and it still doesn't start up.
The side that is loose appears to be designed that way. There is
nothing that would hold it top AND bottom. Gravity keep the top roller
in contact with the rail. A piece as you describe would assist gravity
to hold it in just this position. There is no adj on that roller to
make it bring the sled up. There were no loose pieces in the unit.

I might be able to jury-rig this to make the roller bigger and bring
the sled up.


OK. I think that we have now reached the point where we have exhausted all
the normal possibilities that any of us would be able to think of with this,
which only leaves something very obscure and particular to your player.
Having tried just about everything else, I can see nothing else it can be
bar an internal defect in the laser. If taking out the play on the slide
really does provide a cure, and you're not up for the cost of replacing the
laser, which still just *may* not be the cause of the problem, then as it's
just for yourself, and not a commercial repair, now might be the time to go
for the 'technical bodge' option, as you suggest.

If the slide rod os easily removable, how about encasing it in a piece of
thin heatshrink tubing ? This would increase the effective diameter of the
rod by about the right amount, and give the roller a long life and durable
surface surface to run on.

Arfa
On Thu, 04 Jan 2007 01:15:18 GMT, "Arfa Daily"
wrote:


wrote in message
. ..
NO, I have pushed it to be sure it is all the way in.
The tip is from side to side so gravity is not at work here. A front
to back tip will not cause it to operate.

Also, it will only CONTINUE to play in any position once play is
started. If I tip it to read the TOC then lay it flat it will not
start playing.

I HAVE discovered something else.
The sled rides on 2 rails. one side has a sleeve on it, the other
rests on a roller. It will move up about 1/16 inch on that side. If I
try to start it while flat AND holding that side up it works. Once
started, I have to let it go so the sled can move and it continues to
work.
Since that is not giving me a 45° tip, it does point to the lens or
something inside being too far off to see the reflection in its normal
position. Since it comes back at a 45° tip I have to think something
inside is loose rather than the lens gimble as that only seems to move
in the plane of the CD. HOWEVER, there isn't anything else in the assy
that moves except the lens is there??????????
THEREFORE, it has to be the lens gimble, RIGHT?????????


Weeeeeelllllll ... Not necessarily. Firstly, just because you have
manually
pushed the tray all the way in, that still doesn't say that the whole
loading process has completed correctly. There is often continued movement
to complete the loading cycle, after the tray is fully home. Sometimes,
for
instance, a tray lock slides into place, finally working a switch, to tell
the micro that loading really is complete. However, leaving that aside for
a
moment, I think that you can be pretty sure that a 1/16th inch of vertical
play at one of the slides, is not correct. Are you absolutely sure that
something is not broken or displaced or missing from the mech at that
point
? It's not uncommon for there to be a phosphor bronze finger attached to
the
laser assembly, and resting under the slide rod, to take out just the sort
of play that you are describing. If it definitely works under all
circumstances with the deck flat, but that side of the laser lifted, then
logically, that must be where your problem lies, right ?

Arfa