Archived from groups: alt.video.laserdisc (More info?)

I am working on repairing a Pioneer CLD-2950 laserdisc player.
I've found and replaced a shorted TA8464K focus/tracking driver chip,
however I now discover that the tracking coils on the pickup are
damaged (presumably as a result of the chip failure).

Hence I'm looking for a replacement lens+voicecoil assembly. Buying an
entire new optical pickup (including laser, photodiodes etc) is likely
to be uneconomical. I doubt it's possible to buy just the lens+voicecoil
separately (I have a query in to a spares distributor but am not
hopeful.)

It would, however, be relatively straightforward for me to take the
lens+voicecoil (probably with the suspension wires and terminal block)
out of another pickup to fit in mine. So, is there anyone out there
with an old optical pickup from a CLD-2950 (or similar model that uses
the same pickup). It doesn't need to be a working one, as I don't need
the laser or photodiode array or flex cable or really any of the other
parts that may well be broken in an old discarded pickup. It just
needs to have the lens and the coils underneath intact.

Thanks for your help.

Mike. (In Southampton, UK).
[Remove underscore from my emil address to get my valid address.]

Archived from groups: alt.video.laserdisc (More info?)

>Hence I'm looking for a replacement lens+voicecoil assembly. Buying an
>entire new optical pickup (including laser, photodiodes etc) is likely
>to be uneconomical.

Parts of a laser pickup are not sold separately, and the pickup itself does not
have replaceable parts. Attempts to replace those parts risks further damage
and misalignment of the pickup.

The simple fact of the matter is that the old pickup is totalled and totalled
pickups are unrepairable. It requires replacement, which means both the new
pickup and the player will also require recalibration to get the whole thing to
work properly again.

Buying an old pickup from another CLD-2950 is not a good idea because the
player still has to be recalibrated for that specific pickup. No two pickups
are completely alike, even those of the same part numbers. Every pickup and
every player that a pickup is installed in must be custom calibrated for each
other in order to ensure reliable operation. This is mainly due to the fact
that LaserDisc is analogue FM in nature, so proper calibration is extremely
important.

I repeat my statement that the only truly economical recourse is to consider
the purchase a loss and continue looking for a functional player. - Reinhart

Archived from groups: alt.video.laserdisc (More info?)

In article <20040730222836.06719.00002313@mb-m13.aol.com>, LASERandDVDfan wrote:
>>Hence I'm looking for a replacement lens+voicecoil assembly. Buying an
>>entire new optical pickup (including laser, photodiodes etc) is likely
>>to be uneconomical.
>
>Parts of a laser pickup are not sold separately, and the pickup itself does not
>have replaceable parts. Attempts to replace those parts risks further damage
>and misalignment of the pickup.
>
>The simple fact of the matter is that the old pickup is totalled and totalled
>pickups are unrepairable.

The tracking coils certainly are totalled. However I am someone who considers
most things repairable, given enough time effort and tools.

> It requires replacement, which means both the new
>pickup and the player will also require recalibration to get the whole thing to
>work properly again.

My belief is that the replacing the lens/coils on my existing pickup will
have much less effect on alignment than replacing the whole pickup. After
all, the lens is free floating in operation and the subject of closed
loop servo control to keep it in the right place. I don't intend to disturb
the laser/photodiode/grating/mirror which are precision aligned.

>Buying an old pickup from another CLD-2950 is not a good idea because the
>player still has to be recalibrated for that specific pickup. No two pickups
>are completely alike, even those of the same part numbers. Every pickup and
>every player that a pickup is installed in must be custom calibrated for each
>other in order to ensure reliable operation. This is mainly due to the fact
>that LaserDisc is analogue FM in nature, so proper calibration is extremely
>important.

>I repeat my statement that the only truly economical recourse is to consider
>the purchase a loss and continue looking for a functional player. - Reinhart

If this player is already a total loss, I feel I have little to lose
by trying to fix it myself. (I'll pay postage and something towards an old
pickup, or course, if there's someone out there that can send me one
to use for spares. Thanks.)

Regards,
Mike.

Archived from groups: alt.video.laserdisc (More info?)

Hi Mike.

In order to recalibrate the player with another pickup, at least you'll
need:

The servicemanual.
The Pioneer Test Laserdisk.
An oscilloscope.
A frequence counter.

Good luck with your efforts and please report back with the results.

Best regards
--
Brian Hougaard Baldersbæk
Frejasvej 14
6400 Sønderborg