CD player repair question

[Dave]

MCM sells a replacement Sony CD mechanism (chassis, optical pickup,
tracking motor, spindle motor) for $35 that is used in several brands
of CD players that I frequently see needing service (Numark, Gemini,
Stanton).

The players I've seen have no trimpots for adjustment on their circuit
boards. The only adjustment is the trimpot on the side of the optical
pickup (laser current?)

Does Sony calibrate that trimpot when the replacement mechanism is
built or is adjustment (and special test equipment, knowledge or
service manuals) required after the mechanism is installed in the
player?

Dave







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[Mark D. Zacharias]

If it's really original Sony it's probably adjusted. There's lots of generic
copies out there, though.

If it's been adjusted, there will be some white paint on the potentiometer.

Mark Z.

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"Dave" <trekohio@zoominternet.net> wrote in message
news:231ba0l2tkfpuenttc8d9f13pujj6go7cm@4ax.com...

MCM sells a replacement Sony CD mechanism (chassis, optical pickup,
tracking motor, spindle motor) for $35 that is used in several brands
of CD players that I frequently see needing service (Numark, Gemini,
Stanton).

The players I've seen have no trimpots for adjustment on their circuit
boards. The only adjustment is the trimpot on the side of the optical
pickup (laser current?)

Does Sony calibrate that trimpot when the replacement mechanism is
built or is adjustment (and special test equipment, knowledge or
service manuals) required after the mechanism is installed in the
player?

Dave







-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

 

[LASERandDVDfan]

MCM sells a replacement Sony CD mechanism (chassis, optical pickup,
tracking motor, spindle motor) for $35 that is used in several brands
of CD players that I frequently see needing service (Numark, Gemini,
Stanton).

Sony usually calibrates their CD and DVD optical components at the factory.
They do supply many optical components to several manufacturers, some high end
and some low end.

However, as one poster has indicated, there may be knock-offs that you have to
be aware of. The same poster also mentioned that if all of the pots are marked
with paint, it's likely that they were already calibrated.

The marking is done to indicate the optimal adjustment point and, more
importantly, to keep the adjustments locked in place.

If the pot for the laser gain is not calibrated (which would not be likely if
the replacement part is a genuine Sony product), you'll need a laser power
meter and the appropriate service literature to make adjustments.

There may also be other adjustments on the optical pickup, but these
adjustments are mechanical and will affect how the laser is aimed to the disc.
The appropriate calibration disc, service manual, and an oscilliscope would be
required to perform this kind of calibration. Fortunately, Sony does this
calibration on their replacement pickups at the factory and have them marked so
you shouldn't have to worry about them.

Other adjustments that may be in the CD player itself (tracking gain, tracking
offset, focus gain, focus offset, etc.) will require the proper tools and the
service literature of the player in question from the brand that distributed
the player.

Some CD players that don't have the adjustments mentioned above, which is the
situation in your case. - Reinhart

 

[Mark D. Zacharias]

I have had few problems with the "unadjusted" ones. I just wanted to mention
them as possibly needing adjustment.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"LASERandDVDfan" <laseranddvdfan@aol.com> wrote in message
news:20040515191224.11274.00000878@mb-m20.aol.com...

MCM sells a replacement Sony CD mechanism (chassis, optical pickup,
tracking motor, spindle motor) for $35 that is used in several brands
of CD players that I frequently see needing service (Numark, Gemini,
Stanton).

Sony usually calibrates their CD and DVD optical components at the
factory.
They do supply many optical components to several manufacturers, some high
end
and some low end.

However, as one poster has indicated, there may be knock-offs that you
have to
be aware of. The same poster also mentioned that if all of the pots are
marked
with paint, it's likely that they were already calibrated.

The marking is done to indicate the optimal adjustment point and, more
importantly, to keep the adjustments locked in place.

If the pot for the laser gain is not calibrated (which would not be likely
if
the replacement part is a genuine Sony product), you'll need a laser power
meter and the appropriate service literature to make adjustments.

There may also be other adjustments on the optical pickup, but these
adjustments are mechanical and will affect how the laser is aimed to the
disc.
The appropriate calibration disc, service manual, and an oscilliscope
would be
required to perform this kind of calibration. Fortunately, Sony does this
calibration on their replacement pickups at the factory and have them
marked so
you shouldn't have to worry about them.

Other adjustments that may be in the CD player itself (tracking gain,
tracking
offset, focus gain, focus offset, etc.) will require the proper tools and
the
service literature of the player in question from the brand that
distributed
the player.

Some CD players that don't have the adjustments mentioned above, which is
the
situation in your case. - Reinhart