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/
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