marantz cd6002, help needed

[elet]

Hello everyone,

hope someone out there can give me some suggestions on this issue.
As many others my cd player suddenly began displying "no disc" whatever cd I tried to play.
Looking on the internet I found out several people solved the problem just substituting the whole KSM-213CCM laser mechanism with a brand new one, so I did it.

Now the "no disc" problem ha been solved and the TOC of my cds is read correctly but, when playing, all of them keep skipping!

As the laser is new I guess it can't be because of dust...
Is there anything I could try before taking it to "repair"?
Unfortunately I don't have good electronics knowledge and not even sofisticated instruments...

Thanks a lot in advance for any suggestion,
Matteo

 

[PlasticIsGood]

A dragging sled is one possible cause. Ensure the sliding parts are clean and lightly greased. Use grease intended for plastic, or 100% synthetic at least, possibly from a model shop. Same goes for bevel or worm gears. Sliding parts can stick and then release suddenly, causing a skip.

 

[elet]

Hello,

thanks afor the suggestion.
I lubrificated the sled with oil for sewing machines and now the situation is much much better.
The first tracks (I would say for about 15/20 mins) now play smoothly, without any skip, but in the central part of the record the player starts skipping (sometimes badly, sometimes a little) again.

I will lubrificate also the gears with litium grease, in the hope of a further improvement.

If you should know of some other specific issue which might be the cause for a skipping in the central part, it would be very appreciated.

Thanks again!

Cheers,
Matteo

 

[PlasticIsGood]

Sewing machine oil and lithium grease are both usually mineral-based, and are likely to attack plastic and make it sticky. You should use only 100% synthetic, and it is safest to use products specifically intended for plastic. I suggested a model shop because they will have something like this in stock:

Thunder Tiger Plastic Gear Grease R30/R50/X50/R90 TTRPV0269 on eBay!

Looking at a picture of the mech, there are only two parts that need lubrication, the metal rod that supports the main sliding bearing on the laser mech, and the plastic slider at the other side. Both should be spotlessly clean, and very lightly lubricated. Plastic-safe light grease for the plastic slider. If the main slider on the rod is brass-bushed, then your sewing machine oil is OK as long as it doesn't dribble elsewhere, but a light smear with the grease would be safer.

Moving the sled by hand puts a lot of strain on the gears, and it's hard to feel for drag. If it's easy to remove the motor then do so. String is good for cleaning the rod.

If you are satisfied that the sled is sliding freely for the whole of its travel, and there is still a problem with skipping, then there are many possible causes, I'm afraid.

A CD is read starting in the middle. It reads at a fixed data rate so the rotation speed slows as it plays. Any warping of the disk tends to get worse towards the edge, so the focus mechanism has to work harder to compensate. The sled on the other hand doesn't care where it is as long as it is able to move freely.

If the mechanics are working well and the laser assembly is good, then the problem is likely to be in the circuits controlling turntable speed or focus. Without instruments, I'm afraid you're snookered.