Naim CDI Transport replacement?

[johnm]

Hi!

I have a 12 year old Naim CDI, which uses the rare, and now unavailable Philips CDM4/22 (or CDM4/27) transport mechanism.

This has now 'died' - the motor hardly spins at all, and sometimes even tries to rotate backwards!

I have spoken to Naim, and they quoted around £500 to get it all up and running. Unfortunately I cannot afford this :-(

I know with the CDI that Naim used to install the CDM9 Pro on later models. Being as the CDM9/44 can be used in place of the CDM9 pro, could this be used to bring my CDI back to life? I don't really want to get rid of it!

Cheers,

- John

[zygibajt]

If the laser died , all you have to do is just replace the laser arm from any machine equipped with CDM 4/19, and there are thousands of them out there for as low as 20-30Euro. Mostly Philips and Marantz cheap plastics models. The thing is that your player can have other failure or needs trimming,there is no problem with getting parts for replacement , and they are cheap resourced from those same old and cheap Marantz and Philips players but you might need the person that will be able to do it, will know those players and will also know which one to buy to get the replacement. I would do it for a couple of times cheaper than Naim but I live in Poland , so it's quite far away.
All of players from that era that had those CDM transports had the same chips and servos , so getting the parts is no big deal.

Bartek

P.S. No version of CDM 9 will work as this is quite a bit diffrent transport.

[johnm]

Hi Bartek! Many thanks for your helpful reply! I actually think the laser is OK, it's just the motor not spinning, or barely spinning at all, or sometimes spinning in the opposite direction!

Also the nextel ring has been removed from the hub, which isn't too much of a problem if I use a Naim puck with more than one rubber ring. The spindle has to be from the CDM4/22 or 4/27 though for it's magnetic properties. I tried a 4/19 and the puck would not magnetically 'stick' to the hub at all.

Perhaps I could send you the mechanism on it's own - that way it would be considerably cheaper? It's easily removed from the casing.

Cheers,

- John

[zygibajt]

CDM 4/22 or 4/27 is probably equipped with brushless motor the same as CDM1MKII and CDM2, but quite diffrent from CDM 4.

Also, I suppose the failure will be not in the motor itself but in electronics driving it that are located on the main board (I've had similar failures before). Can you get a close pictures of the CD inside? So I can closely see the transport and the main board with the chips. If not on the forum you can send them to zygibajt@o2.pl

Bartek

[johnm]

Hi!

I'll get the camera out this evening and take some snaps, then e-mail them to you!

Thanks a million!

- John

[tubenut]

I would agree that there is a likely problem with the driving electronics for the CDM, however, CDMs can go a bit stuppid if the laser is not reading the disc. Having played with some std Marantz/Philips CDM4/19 players has also shown me that if you lift the clamp during play and the CD slips a little, this can also send the unit bonkers. So if the rubber grippy stuff obn the spindle is deteriorated it could cause some problems but only if the thng actually tries to spin up and gets to a fair speed.


WRT swapping lasers/mechs. I have with some "force" removed a CDM4 spindle before but yours has the deteriorated rubber problem as well so getting a new cdm4 and then swapping the magnetic spindle may be a waste of time as your spindle is dodgy.

The cdm9/44 plastic spindle also uses a magnet and I think one could remove this magnet out of the plastic and glue it into a std CDM4 spindle.

I may have a CDM9 spindle spare but I am in South Africa and I would have to look in the boxes and boxes and boxes....


If you can get your hands on a working CDM4 for little money I would get one and fit it into the naim. You can "clamp" a CD down with a little blue tack on the spindle. This at least will tell you if you have a laser/motor problem or an electronic one.... And you can always hamster the laser for the future if the pronblem is electronic....

[johnm]

Hi!

I don't seem to have a problem with CD slippage, as the puck holds the CD down pretty well. Also I have a very thin rubber washer which I can use for any problem discs, so I don't think disc slippage is the problem.

I think maybe - as you've both suggested - it's either a driver board problem, or something wrong with the motor.

With Bartek's kind help I'm going to have a go at replacing the laser assembley with one from a CDM4/19 and see if this makes a difference. If not that just leaves the motor I guess. I will try your idea first though of just running the CDM 4/19 in there with a make-shift CD clamp just to see if it's the driver board, or mechanism which is at fault.

Thanks for your help, and wish me luck ;-)

- John

[tubenut]

What would be luck? If it works with the 4/19 and sticky goop as a clamp? Well, I guess then you would build the laser across on the naim CDM and hope it is the laser......

[tubenut]

Use a paper clip to short the flex foil while you are handling the laser and only remove the clip at the last moment when you plug it into the servo pcb!!!

[tubenut]

I dug this stuff out and my idea of using the 9 spindle's magnet will not work as it's dia is to large. You could probably file it down to fit but it will probably be easier to try and find a circular little magnet to fit onto the CDM4/19 spindle.... (If that is where your problem is..)

Let us know how you progressed!

G