problem with cdm 12.1
 

hello all!!

i have got a quite old (10 years) marantz cd player with a cdm 12.1
laser unit.
i have gone through various faqs and threads and couldn't find a
solution for my problem, which is:

the unit reads a cd normally and displays the TOC. also playing the cd
works fine for a while. after 90 secs there is some noise, that has
more or less the periodicity of the disc rotation, getting
increasingly louder and louder, till the unit stops playback and
either says "no discs" or displays the TOC again.
repeatingly starting playback after the problem, shortens the period
between the occurrences of the problem. waiting for about 3-5 minutes
gets me back to the status quo (90 secs until the first error).

i guess that perhaps the focus would have to be adjusted, but
unfortunately i couldn't find any potentiometer, neither on the
platine nor on the unit itself.

i know that this cdm 12.1 is a quite cheap laser unit, but actually, i
would just like to repair it, even if its difficult.

so if anyone has any suggestions, experiences, or useful links, please
post them.

thanks in advance

yours philipp

1. there is no repair or adjustments available on the cdm12.1
2. Look for the spindle platter being pushed down and rubbing, a slight
pull up on it may fix the problem.

Other than the spindle platter getting pushed down, your fix is to
replace the cdm 12.1 assembly. That was the repair part and procedure
for the unit.

David

philipp wrote:
hello all!!

i have got a quite old (10 years) marantz cd player with a cdm 12.1
laser unit.
i have gone through various faqs and threads and couldn't find a
solution for my problem, which is:

the unit reads a cd normally and displays the TOC. also playing the
cd
works fine for a while. after 90 secs there is some noise, that has
more or less the periodicity of the disc rotation, getting
increasingly louder and louder, till the unit stops playback and
either says "no discs" or displays the TOC again.
repeatingly starting playback after the problem, shortens the period
between the occurrences of the problem. waiting for about 3-5 minutes
gets me back to the status quo (90 secs until the first error).

i guess that perhaps the focus would have to be adjusted, but
unfortunately i couldn't find any potentiometer, neither on the
platine nor on the unit itself.

i know that this cdm 12.1 is a quite cheap laser unit, but actually,
i
would just like to repair it, even if its difficult.

so if anyone has any suggestions, experiences, or useful links,
please
post them.

thanks in advance

yours philipp

Philipp,

In general, you'll probably need to replace the mechanism, which can be
replaced with a VAM-1201 for around $25 US. You could try removing the
grease that has probably turned into brown putty on the sled rails and
its drive. I use a light machine oil to relubricate. (Synthetic 5W-30
or 10W-30/40 motor oil is OK) You have to take the gear and sled motor
out to really clean everything.

As another poster mentioned, make sure that the spindle motor spins
freely, and has not been pressed down too far on the shaft. Also make
sure that there is no debris on the spindle platter OR the clamper.
There is a magnet (I forget if it is on the spindle platter or clamper)
which can grab small bits of magnetic debris and then the disc will not
seat properly.

philipp wrote:

hello all!!

i have got a quite old (10 years) marantz cd player with a cdm 12.1
laser unit.
i have gone through various faqs and threads and couldn't find a
solution for my problem, which is:

the unit reads a cd normally and displays the TOC. also playing the cd
works fine for a while. after 90 secs there is some noise, that has
more or less the periodicity of the disc rotation, getting
increasingly louder and louder, till the unit stops playback and
either says "no discs" or displays the TOC again.
repeatingly starting playback after the problem, shortens the period
between the occurrences of the problem. waiting for about 3-5 minutes
gets me back to the status quo (90 secs until the first error).

i guess that perhaps the focus would have to be adjusted, but
unfortunately i couldn't find any potentiometer, neither on the
platine nor on the unit itself.

i know that this cdm 12.1 is a quite cheap laser unit, but actually, i
would just like to repair it, even if its difficult.

so if anyone has any suggestions, experiences, or useful links, please
post them.

thanks in advance

yours philipp

Does sound like the laser pickup assy really..
As it warms up progressively distorted sound appears then the unit stops-
seen it many times... never fixed the old laser- only answer is a
replacement. I suspect theres one of the sensors going weak as it warms up.

AW


"Tim Schwartz" wrote in message
...
Philipp,

In general, you'll probably need to replace the mechanism, which can be
replaced with a VAM-1201 for around $25 US. You could try removing the
grease that has probably turned into brown putty on the sled rails and
its drive. I use a light machine oil to relubricate. (Synthetic 5W-30
or 10W-30/40 motor oil is OK) You have to take the gear and sled motor
out to really clean everything.

As another poster mentioned, make sure that the spindle motor spins
freely, and has not been pressed down too far on the shaft. Also make
sure that there is no debris on the spindle platter OR the clamper.
There is a magnet (I forget if it is on the spindle platter or clamper)
which can grab small bits of magnetic debris and then the disc will not
seat properly.

philipp wrote:

hello all!!

i have got a quite old (10 years) marantz cd player with a cdm 12.1
laser unit.
i have gone through various faqs and threads and couldn't find a
solution for my problem, which is:

the unit reads a cd normally and displays the TOC. also playing the cd
works fine for a while. after 90 secs there is some noise, that has
more or less the periodicity of the disc rotation, getting
increasingly louder and louder, till the unit stops playback and
either says "no discs" or displays the TOC again.
repeatingly starting playback after the problem, shortens the period
between the occurrences of the problem. waiting for about 3-5 minutes
gets me back to the status quo (90 secs until the first error).

i guess that perhaps the focus would have to be adjusted, but
unfortunately i couldn't find any potentiometer, neither on the
platine nor on the unit itself.

i know that this cdm 12.1 is a quite cheap laser unit, but actually, i
would just like to repair it, even if its difficult.

so if anyone has any suggestions, experiences, or useful links, please
post them.

thanks in advance

yours philipp

thankyou all for your quick and professional respones!
i tried all the things that you proposed but unfortunately it still
not works.
really souds as if i will have to exchange it.
i heard i can use cdm 12.1 again or vam 1201. any else? which of the
two is "better" (i guess they are pretty the same...)

thanks again

philipp

The VAM 1201 replaces the CDM12.1 according to Philips, so the VAM1201
is current, and the CDM-12.1 is obsolete. I can't say that I've noticed
any difference in performance, and I've no idea about how long they will
last.

Regards,
Tim


philipp wrote:

thankyou all for your quick and professional respones!
i tried all the things that you proposed but unfortunately it still
not works.
really souds as if i will have to exchange it.
i heard i can use cdm 12.1 again or vam 1201. any else? which of the
two is "better" (i guess they are pretty the same...)

thanks again

philipp