problems with my Adcom CD player

[Shaun]

Hello,

I have a used ADCOM GCD-700 5 disk CD player that was given to me and it is
overly sensitive to vibrations, bumps and slight scratches on the CDs. I've
mounted it on vibration absorbing rubber and this has greatly impoved its
bump and vibration sensitivity, but it is still very sensitive to the
slightest mark or scratch on cds. How can I cure this.

thanks in advance,

Shaun

 

[Tim Schwartz]

Hello,

I have a used ADCOM GCD-700 5 disk CD player that was given to me and it is
overly sensitive to vibrations, bumps and slight scratches on the CDs. I've
mounted it on vibration absorbing rubber and this has greatly impoved its
bump and vibration sensitivity, but it is still very sensitive to the
slightest mark or scratch on cds. How can I cure this.

thanks in advance,

Shaun

Shaun,

If this machine is as old as I think it is, then its not worth putting
any serious money into it. There is likely a manufacturing date on the
machine that will give the month and year it was made. Make sure if
there are any transit screws on the bottom they are removed or in the
released position.

You could try cleaning the lens and the disc platter. You'd have to
open the machine to do this. the lens is about the size of a pencil
eraser, and is on a suspension, so be gentle with it. I use a cotton
swab moistened with lens cleaning fluid, though Windex will probably do.
I also clean off the platter that the disc sits on while spinning.
I've seen enough debris build up on the platter over time that it no
longer lets the disc sit flat, and that can cause all kinds of grief.
Again, a moistened swab or slightly damp cloth is all you need to clean it.

Beyond that, you are likely to have a worn out laser, which is likely
to be more expensive to replace than the machine is worth.

Regards,
Tim Schwartz
Bristol Electronics

 

[Shaun]

Shaun,

If this machine is as old as I think it is, then its not worth putting any
serious money into it. There is likely a manufacturing date on the
machine that will give the month and year it was made. Make sure if there
are any transit screws on the bottom they are removed or in the released
position.

You could try cleaning the lens and the disc platter. You'd have to open
the machine to do this. the lens is about the size of a pencil eraser,
and is on a suspension, so be gentle with it. I use a cotton swab
moistened with lens cleaning fluid, though Windex will probably do. I also
clean off the platter that the disc sits on while spinning. I've seen
enough debris build up on the platter over time that it no longer lets the
disc sit flat, and that can cause all kinds of grief. Again, a moistened
swab or slightly damp cloth is all you need to clean it.

Beyond that, you are likely to have a worn out laser, which is likely to
be more expensive to replace than the machine is worth.

Regards,
Tim Schwartz
Bristol Electronics

This CD player is a higher quality model and one of the only multidisk units
that uses high quality components. Mechanically it's not made very well
though, but the electronic audio stages are all class A, so it's worth my
time and some money to try to fix it.

Thanks for your reply.

Shaun

 

[Shaun]

First, clean out any crud from the laser head assembly. If that
doesn't improve things, replace it. That's a 1997 vintage machine so
parts may be tricky to find... Oh, too easy:
<http://www.adcomparts.com/part.php?item=46001400>
However, I don't think it's worth $50 to fix something that old.

More:
<http://www.fixya.com/support/p134391-adcom_gcd_700_5_disc_cd_changer>
<http://www.fixya.com/support/t648590-adcom_gcd_700_tracking_problems>

--
Jeff Liebermann [email protected]
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Thanks for the links, I'll probably order a new laser head for it, but first
I'll lake it apart and clean the lenses.

Shaun

 

[Mark Zacharias]

Thanks for the links, I'll probably order a new laser head for it, but
first I'll lake it apart and clean the lenses.

Shaun

Absolutely clean it. Should help.

Mark Z.

 

[N_Cook]

Thanks for the links, I'll probably order a new laser head for it, but first
I'll lake it apart and clean the lenses.

Shaun

Then after cleaning and before ditching. Find the "power pot" ,measure
resistance with a DVM , "both ways" in case of a difference, so you can get
back to that value. Change the value , no more than 5 percent, to see if it
improves error proneness

 

[N_Cook]

It's not quite that straightforward on a '240, as there are three pots on
there, and considerable interaction between them. I would not recommend
touching them, as at least one of them is *extremely* critical in its
setting to get the thing to play at all.

Arfa

Which implies 3 analoguey things that could drift over time. I would take 3x
0.1 percent measurements and tabulate some twiddlings v drop-out time of a
known bad ie deliberately scratched track on a CD. As last legs anyway,
nothing to loose except a bit of time

 

[Shaun]

Which implies 3 analoguey things that could drift over time. I would take
3x
0.1 percent measurements and tabulate some twiddlings v drop-out time of a
known bad ie deliberately scratched track on a CD. As last legs anyway,
nothing to loose except a bit of time

I'm sure I can find a few CDs that are scratched in my collection.

shaun