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Sony CDP-C335 carousel doesn't align with clamping assembly.

D

David Farber

Jan 1, 1970
0
This Sony CDP-C335 is just a few millimeters away from working properly.
When the 5 disk carousel rotates the CD into place, the clamping mechanism
closes but the metal pin in the clamping mechanism which is supposed to line
up with the hole in the carousel is not lining up properly. It either makes
a loud snapping noise as the pin forces its way through the hole in the
carousel or the clamping mechanism jams completely as it cannot force its
way into place since the alignment between the two is off. The belt in the
carousel mechanism has good tension and is not slipping. Anyone seen this
problem before?

Thanks for your reply.
 
D

David Farber

Jan 1, 1970
0
Arfa said:
You know, I rather think I have, but I can't for the life of me
remember what was causing it. Was it a mechanical alignment issue
maybe ? I have a dim recollection of something geared being a tooth
out. A further dim recollection is of letting it settle in the jammed
position, then de-powering and undoing the screw in the centre of the
carousel, and lifting it to disengage it from its drive so that it
could be rotated to line up correctly, before dropping it down again,
and refitting the screw. I might be thinking of something else
entirely, but something is chiming deep in the shadowy recesses of
what passes for my mind ... :)
Arfa

From what I can tell, there are some optical sensors that monitor the
position of the carousel. So removing the carousel and then repositioning it
shouldn't really matter. When I removed the carousel to inspect the belt, I
reinstalled it so it was centered. I'm wondering since it's always hitting
the trailing edge of the hole, perhaps the carousel isn't braking soon
enough after the uP turns off the carousel motor?

Thanks for your reply.
 
M

Mark Zacharias

Jan 1, 1970
0
David Farber said:
This Sony CDP-C335 is just a few millimeters away from working properly.
When the 5 disk carousel rotates the CD into place, the clamping mechanism
closes but the metal pin in the clamping mechanism which is supposed to
line up with the hole in the carousel is not lining up properly. It either
makes a loud snapping noise as the pin forces its way through the hole in
the carousel or the clamping mechanism jams completely as it cannot force
its way into place since the alignment between the two is off. The belt in
the carousel mechanism has good tension and is not slipping. Anyone seen
this problem before?

Thanks for your reply.

I think I would look at the flat wire from the carousel down to the main
board. Seen a few bad, and the opto-sensing would certainly be affected by
this.

Mark Z.
 
D

David Farber

Jan 1, 1970
0
Mark Zacharias said:
I think I would look at the flat wire from the carousel down to the main
board. Seen a few bad, and the opto-sensing would certainly be affected by
this.

Mark Z.

Hi Mark,

The flat wire checks ok. I've looked around this area and the only
suspicious thing I've found is that the carousel has a lot of loose travel
in it when it's at rest. I measured about 2.5mm of wiggle room at the
circumference of the carousel. That's plenty of error to cause problems. I
think the intermediate gear between the worm gear and the carousel is worn
out. It's location #66 on the parts blowup on page 22 of the service manual
here:
http://www.electronica.ro/service_manuals/sony/compact_disk_player/cdp-c335/

Thanks for your reply.
 
This problem is usually 1 of 2 things.

1) The gears are outof timing by 1 tooth.
2) The green flat cable that goes fro the deck to the board is defective. This won't be visible as the connections are intermittant. Replace the cable first. This may resolve the problem.

Dan
 
D

David Farber

Jan 1, 1970
0
This problem is usually 1 of 2 things.

1) The gears are outof timing by 1 tooth.
2) The green flat cable that goes fro the deck to the board is
defective. This won't be visible as the connections are
intermittant. Replace the cable first. This may resolve the
problem.

Dan

Hi Dan,

The position of the carousel is controlled by the photo transistors. When
the slits underneath the carousel line up in whatever formation the uP is
looking for, the carousel motor stops turning. When the unit is powered up
from an unplugged condition, the carousel spins and orients itself so that
disk 1 is facing the user. In that respect, it doesn't matter what position
the carousel is in when the unit is powered up, it can figure out where each
disk is and how far to spin the carousel. I don't understand how a defective
cable could cause the carousel to be misaligned by a couple of millimeters.
Don't you think it would totally lose track of its position if the cable
were bad?

So taking that all into consideration, I took some needle nose pliers and
slightly tweaked the metal pin that was misaligned with the hole in the
carousel. Now it fits just fine when the cam elevates the play mechanism
into position.

Thanks for your reply.
 
The cable I described developes cracks with age. This causes intermittant connections withint hte cable. I have repaired a number of these units, some of which had the problem you described. Some of these also were "fixed" by replacing the cable. The cable is by no means the only cause of hte problem you describe. The photo trnasistors can be bad, the digital transistors (DTC) that "digitize" the transition can be faulty as well. The bottom line here is that there are many potential causes of the problem. Experience will provide you with clues (as I and others posted here).

A cam gear off by 1 tooth can cause this problem as well. Obtain the service manual which contains the alignment marks to verify proper alignment of the tray as well.

Dan
 
W

William Sommerwerck

Jan 1, 1970
0
So taking that all into consideration, I took some needle nose pliers and
slightly tweaked the metal pin that was misaligned with the hole in the
carousel. Now it fits just fine when the cam elevates the play mechanism
into position.

I say -- without sarcasm -- that it's gratifying when common sense works.
(It so rarely does when servicing electronic equipment.)

The reason this wasn't solved sooner was that there was no obvious /reason/
why the pin should have been misaligned in the first place. How /could/ it
have gotten misaligned?

I had a similar problem 40 years ago. I pulled out my Nikon F and discovered
the film advance was jammed. It turned out the take-up hub had been BENT at
the middle, as if someone had banged it with a mallet. How did it happen? I
never learned.
 
D

David Farber

Jan 1, 1970
0
The cable I described developes cracks with age. This causes
intermittant connections withint hte cable. I have repaired a number
of these units, some of which had the problem you described. Some of
these also were "fixed" by replacing the cable. The cable is by no
means the only cause of hte problem you describe. The photo
trnasistors can be bad, the digital transistors (DTC) that "digitize"
the transition can be faulty as well. The bottom line here is that
there are many potential causes of the problem. Experience will
provide you with clues (as I and others posted here).

A cam gear off by 1 tooth can cause this problem as well. Obtain the
service manual which contains the alignment marks to verify proper
alignment of the tray as well.

Dan

Hi Dan,

I'll recheck the timing again. Though I don't understand what the timing of
the cam that closes and opens the drawer and raises and lowers the play
mechanism has to do with the positioning of the carousel. I've worked on
enough of these carousel players to know that when the timing is off by one
tooth in one direction, the drawer closes all the way while the cam is still
continuing to try and push it even further. As a result, the cam gets jammed
and that's the end of that loading cycle. If it's off by one tooth in the
other direction, the clamping assembly will bite down on the disk before
it's pushed all the way to the back of the mechanism. Neither of these
faults has anything to do with the rotation of the carousel as far as I can
tell.
Also, I'll try and find a way to put a scope probe on the photo transistors
and see if there's a clean signal coming off of there.

Thanks for your reply.
 
D

David Farber

Jan 1, 1970
0
William said:
I say -- without sarcasm -- that it's gratifying when common sense
works. (It so rarely does when servicing electronic equipment.)

The reason this wasn't solved sooner was that there was no obvious
/reason/ why the pin should have been misaligned in the first place.
How /could/ it have gotten misaligned?

I had a similar problem 40 years ago. I pulled out my Nikon F and
discovered the film advance was jammed. It turned out the take-up hub
had been BENT at the middle, as if someone had banged it with a
mallet. How did it happen? I never learned.

The pin probably wasn't misaligned in the CD player. Anywhere along the line
there could have been something that was warped. But the easiest way to
correct it was to just tweak the pin.

By the way, that Nikon F is a sweet camera. (-:


Thanks for your reply.
 
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