Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Pioneer CLD-92 not reading laser disks

This high end laser disk player from 1990 plays CDs fine, but when a
LD is inserted, it only spins for a few revolutions before it ejects
it. My first instinct would be to say the optical pickup is bad, but
other LD players I've seen with problems try a lot harder to play
before giving up. I don't think it's the spindle motor because when
it's playing a CD it has plenty of torque (I actually can't slow down
the disc by holding the spindle). The pickup moves freely and the
tilt motor is working. Since I don't have a service manual, I'd like
to hear any ideas before I really dive into it.
Andy Cuffe


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Default Pioneer CLD-92 not reading laser disks

Andy Cuffe writes:

This high end laser disk player from 1990 plays CDs fine, but when a
LD is inserted, it only spins for a few revolutions before it ejects
it. My first instinct would be to say the optical pickup is bad, but
other LD players I've seen with problems try a lot harder to play
before giving up. I don't think it's the spindle motor because when
it's playing a CD it has plenty of torque (I actually can't slow down
the disc by holding the spindle). The pickup moves freely and the
tilt motor is working. Since I don't have a service manual, I'd like
to hear any ideas before I really dive into it.


So the spindle motor on this one is used for both LDs and CDs?

With only a few revolutions and I assume never getting up to speed, it
can't even know if the LD is valid so sounds like it may be shutting
down due to another problem.

There is also the newsgruop alt.video.laserdisc though they don't do
much in the way of repair there.

--- 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

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Default Pioneer CLD-92 not reading laser disks

On 22 May 2007 08:56:26 -0400, Sam Goldwasser
wrote:

Andy Cuffe writes:

This high end laser disk player from 1990 plays CDs fine, but when a
LD is inserted, it only spins for a few revolutions before it ejects
it. My first instinct would be to say the optical pickup is bad, but
other LD players I've seen with problems try a lot harder to play
before giving up. I don't think it's the spindle motor because when
it's playing a CD it has plenty of torque (I actually can't slow down
the disc by holding the spindle). The pickup moves freely and the
tilt motor is working. Since I don't have a service manual, I'd like
to hear any ideas before I really dive into it.


So the spindle motor on this one is used for both LDs and CDs?

With only a few revolutions and I assume never getting up to speed, it
can't even know if the LD is valid so sounds like it may be shutting
down due to another problem.

There is also the newsgruop alt.video.laserdisc though they don't do
much in the way of repair there.


Yes, it uses the same motor for both which is obviously massive
overkill for CD playback. Since it has lots of torque when playing a
CD, I would think it could spin a LD faster than it does.

It never gets faster than about 10 RPM when loading a LD. I can see
some RF at the test point (although way below its normal frequency due
to the low speed), so it must be more or less focusing.

It seems strange that it gives up so fast. Other LD players will
grind away for a couple of minutes when they have trouble playing a
disc. It's also odd that it ejects the disc when it fails. I'm
hoping someone can tell me what this model normally does when it can't
play a LD.

I've already checked for obvious problems such as power supply
voltages and gross mechanical problems. I'll double check for sensor
problems that might be causing it to reject the disc.
Andy Cuffe


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Default Pioneer CLD-92 not reading laser disks

Andy Cuffe writes:

On 22 May 2007 08:56:26 -0400, Sam Goldwasser
wrote:

Andy Cuffe writes:

This high end laser disk player from 1990 plays CDs fine, but when a
LD is inserted, it only spins for a few revolutions before it ejects
it. My first instinct would be to say the optical pickup is bad, but
other LD players I've seen with problems try a lot harder to play
before giving up. I don't think it's the spindle motor because when
it's playing a CD it has plenty of torque (I actually can't slow down
the disc by holding the spindle). The pickup moves freely and the
tilt motor is working. Since I don't have a service manual, I'd like
to hear any ideas before I really dive into it.


So the spindle motor on this one is used for both LDs and CDs?

With only a few revolutions and I assume never getting up to speed, it
can't even know if the LD is valid so sounds like it may be shutting
down due to another problem.

There is also the newsgruop alt.video.laserdisc though they don't do
much in the way of repair there.


Yes, it uses the same motor for both which is obviously massive
overkill for CD playback. Since it has lots of torque when playing a
CD, I would think it could spin a LD faster than it does.

It never gets faster than about 10 RPM when loading a LD. I can see
some RF at the test point (although way below its normal frequency due
to the low speed), so it must be more or less focusing.

It seems strange that it gives up so fast. Other LD players will
grind away for a couple of minutes when they have trouble playing a
disc. It's also odd that it ejects the disc when it fails. I'm
hoping someone can tell me what this model normally does when it can't
play a LD.

I've already checked for obvious problems such as power supply
voltages and gross mechanical problems. I'll double check for sensor
problems that might be causing it to reject the disc.
Andy Cuffe


It does realize it's an LD in there and not a CD, right?

With any RF, it's focusing. I assume you mean 10 rps. I doubt there is
any way it can conclude the LD is bad at 10 rps. I assume you've tried
more than one LD.

--- 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.
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Default Pioneer CLD-92 not reading laser disks

On 31 May 2007 19:30:37 -0400, Sam Goldwasser
wrote:


It does realize it's an LD in there and not a CD, right?

With any RF, it's focusing. I assume you mean 10 rps. I doubt there is
any way it can conclude the LD is bad at 10 rps. I assume you've tried
more than one LD.


It does correctly say LD in the display. I actually do mean 10 RPM!
It's a stretch to call it RF at that speed, but there's a definite
signal at the test point. I compared it to a different LD player and
it spins up the disc as soon as it detects it.

It's definitely a problem with the LD spindle servo which is separate
from the CD servo. There's virtually no voltage on the LD spindle
error line (which is labeled on the board). I tried applying an
external voltage to it through a 10 k resistor and the spindle motor
immediately came up to speed (of course, not in sync). I traced the
error signal back through an amplifier circuit and everything seems
fine there. It then goes back to a large custom IC.

By this time, the player was working better than before. It was
actually spinning the disc at almost the right speed and produced
intermittent video. After allowing it to cool down it was exactly as
it was before. Leaving it turned on in stop mode for about 30 minutes
is enough to get it to start partially working again.

Clearly there's a thermal problem. Hopefully just an electrolytic
somewhere. A couple of times it has suddenly turned itself off
without warning (as if I had pulled the plug). I'm going to pull the
power supply and also check the various regulator circuits scattered
around the other boards. Fortunately, unlike most Pioneer LD players,
most of the boards are accessible while the player is assembled.
Andy Cuffe




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Default Pioneer CLD-92 not reading laser disks

Andy Cuffe writes:

On 31 May 2007 19:30:37 -0400, Sam Goldwasser
wrote:


It does realize it's an LD in there and not a CD, right?

With any RF, it's focusing. I assume you mean 10 rps. I doubt there is
any way it can conclude the LD is bad at 10 rps. I assume you've tried
more than one LD.


It does correctly say LD in the display. I actually do mean 10 RPM!
It's a stretch to call it RF at that speed, but there's a definite
signal at the test point. I compared it to a different LD player and
it spins up the disc as soon as it detects it.

It's definitely a problem with the LD spindle servo which is separate
from the CD servo. There's virtually no voltage on the LD spindle
error line (which is labeled on the board). I tried applying an
external voltage to it through a 10 k resistor and the spindle motor
immediately came up to speed (of course, not in sync). I traced the
error signal back through an amplifier circuit and everything seems
fine there. It then goes back to a large custom IC.

By this time, the player was working better than before. It was
actually spinning the disc at almost the right speed and produced
intermittent video. After allowing it to cool down it was exactly as
it was before. Leaving it turned on in stop mode for about 30 minutes
is enough to get it to start partially working again.

Clearly there's a thermal problem. Hopefully just an electrolytic
somewhere. A couple of times it has suddenly turned itself off
without warning (as if I had pulled the plug). I'm going to pull the
power supply and also check the various regulator circuits scattered
around the other boards. Fortunately, unlike most Pioneer LD players,
most of the boards are accessible while the player is assembled.


Freeze spray time!

--- 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.

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Default Pioneer CLD-92 not reading laser disks

On Jun 1, 1:34 pm, Andy Cuffe wrote:
On 31 May 2007 19:30:37 -0400, Sam Goldwasser
wrote:



It does realize it's an LD in there and not a CD, right?


With any RF, it's focusing. I assume you mean 10 rps. I doubt there is
any way it can conclude the LD is bad at 10 rps. I assume you've tried
more than one LD.


It does correctly say LD in the display. I actually do mean 10 RPM!
It's a stretch to call it RF at that speed, but there's a definite
signal at the test point. I compared it to a different LD player and
it spins up the disc as soon as it detects it.

It's definitely a problem with the LDspindleservo which is separate
from the CD servo. There's virtually no voltage on the LDspindle
error line (which is labeled on the board). I tried applying an
external voltage to it through a 10 k resistor and thespindlemotor
immediately came up to speed (of course, not in sync). I traced the
error signal back through an amplifier circuit and everything seems
fine there. It then goes back to a large custom IC.

By this time, the player was working better than before. It was
actually spinning the disc at almost the right speed and produced
intermittent video. After allowing it to cool down it was exactly as
it was before. Leaving it turned on in stop mode for about 30 minutes
is enough to get it to start partially working again.

Clearly there's a thermal problem. Hopefully just an electrolytic
somewhere. A couple of times it has suddenly turned itself off
without warning (as if I had pulled the plug). I'm going to pull the
power supply and also check the various regulator circuits scattered
around the other boards. Fortunately, unlike mostPioneerLD players,
most of the boards are accessible while the player is assembled.
Andy Cuffe




How much voltage? I have the exact same problem on a CLD95. 0 voltage
and no signal on the error line but when I applied 2 volts to the
error line the spindle motor starts to spin up for a few seconds.

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Default Pioneer CLD-92 not reading laser disks

On Mon, 11 Jun 2007 12:33:04 -0700, 1ziggi1 wrote:




How much voltage? I have the exact same problem on a CLD95. 0 voltage
and no signal on the error line but when I applied 2 volts to the
error line the spindle motor starts to spin up for a few seconds.


I've set this project aside for a while. I will post back if I make
any progress. It's not a high priority at the moment.
Andy Cuffe


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Default Pioneer CLD-92 not reading laser disks

On Mon, 21 May 2007 11:22:52 -0700, Andy Cuffe
wrote:

This high end laser disk player from 1990 plays CDs fine, but when a
LD is inserted, it only spins for a few revolutions before it ejects
it. My first instinct would be to say the optical pickup is bad, but
other LD players I've seen with problems try a lot harder to play
before giving up. I don't think it's the spindle motor because when
it's playing a CD it has plenty of torque (I actually can't slow down
the disc by holding the spindle). The pickup moves freely and the
tilt motor is working. Since I don't have a service manual, I'd like
to hear any ideas before I really dive into it.
Andy Cuffe




I found a beat up, but working low end model with the same transport.
To cut a long story short, it was the pickup. Swapping the pickup
from the parts machine into the CLD-92 got it working. It didn't even
need any alignment.

Andy Cuffe


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