Naim CDI Transport replacement?

[et]

thank you, i will pass that along to him. I don't really understand how the transport breaks down into components, but I guess I am wondering if the cdm4/19 can be broken down to some major component level for the laser portion of the transport to replace what is in my player today. Maybe not just the laser, but obviously with leaving the motor in place, as that is an uncommon cdm4 version part. I also assume the version 19 and mine in the cds1 (a version 21 or 27 i think) would have different mounting locations. I guess it is a question of how people have used different cdm4 version transports to repair their transports on this board? thanks have a good weekend.
Tim

[anatech]

Hi Tim,
The slash code represented mechanism options. I haven't paid a great deal of attention to these as I found working on the earlier versions to be a pain (Revox, Marantz). I am sure there is some else who has more experience on these.

Most of my service has to do with servo problems and the odd broken flexible cable. But your tech should proceed by checking the simplest things first instead of jumping around.

-Chris

[Peter Braroe]

Hello!

Well after some more testing my CDI is still not working 100% - i ordered a new puck but didn't recieve it yet so that may fix things. The laser measures OK so i am wondering if it's the motor?

It seems to me that the permanent magnet would be demagnetized over the years and use... and that that could be it. Anyone have any theories/experiences about this?

If it is the motor what other motors could be used as replacement? Anyone have a spare motor?

The spindle on which the CD sits has a "cup" underneath and inside that there is a permanent magnet in the shape of a ring.

I am thinking about remagnetizing the ring... but I don't know exactly how it's magnetized - anyone know how this works?

A magnetizer is "easy" to build - some copper wire and a big capacitor!

I have been reading up on brushless DC motors here
http://www.ibiblio.org/obp/electricC...html#02461.png

And here
http://www.s-line.de/homepages/bosch...ess/node9.html

Ideas?

/Peter

[anatech]

Hi Peter,
The disc motor can be tested. Spin by hand with a CD on it and listen for knocking or rattling (bad bearings). Secondly, use a scope to look at the motor drive waveforms with a scope. Those two tests should tell you for sure whether the motor is good or not.

-Chris

[Peter Braroe]

OK,

I will get my scope out and test it - do you know what to look for? I.e. what is good waveform/voltages? And what is the characteristic of bad?

When I had the CD player apart and it "acted up" i.e. unsucsessfully trying to find a track I tried to gently pinch the puck to brake it somewat - and then it mostly found the track.

There is a trimpot by the motor also - anyone know what that one does?

Could be unrelated though...

/Peter

[anatech]

Hi Peter,
A defective wave form will have a characteristic with an exception. Could be a missing section of pulse or a higher part depending on whether it has a shorted or open winding. A brushless motor still has coils that can be tested.

I don't have any clue what that pot might do, I don't have any service information. A general rule of thumb is to leave all adjustments alone. It worked with them in their current positions so something else is at fault.

Do not adjust anything without a very good reason! That and you need to know precisely what you are doing!
-Chris

[poobah]

It is highly unlikely that your magnet has any problems. BTW building a mag fixture is intensely difficult... I have done many.

If you are curious take a small magnet near the motor and see if the motor moves in sympathy.

[Web Wolf]

Hi boys, I've a similar problem because I bought a NAIM CDi in ebay a little time ago and now the player, when I insert a cd, try to read it and then it writes an error message. NAIM assistance says that the problem is that the lens in exhausted. As I found here, I should have the CDM4/27 mechanic. I found a CDM4/19. Really if I replace the laser it will work again ? What are the differences between mechanics ?

The assistance said to me that often similar mechanics didn't work on NAIM players.

Please help me !!!

[adgrimes]

I recently moved house, and decided to set up my Naim gear again (previous house didn't allow me to do this - too small).

I too am seeing the CD skipping and ERR'ing issue on my CDI. I decided to do a quick search for nextel ring fixes. Im pretty sure the nextel ring is the issue with my CDI, as trying the rubber glove trick fixes it 80% of the time...
I noticed someone say on here that the Naim CD5i puck fixes this problem?

I have a few questions regarding this:
1. Does anyone know of somewhere to get hold of a CD5i puck?
2. It appears Naim sell the CD5si puck as a spare part. Was there a difference with the CD5i and the CD5si puck, and if not will the CD5si puck do the trick?
3. Do i need to attempt to replace the magnet part on the transport as well as the puck itself? My guess is no, but figured I'd ask anyway

Many Thanks!

[martin clark]

Ad - if you are in the UK maybe contact James at Tom Tom (I have no affiliation but they are very helpful)

Naim Pucks for sale

And no, you leave the turntable magnet alone.