Transport identification and fixes?

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Hi, is anyone here able to identify this transport?

An externally hosted image should be here but it was not working when we last tested it.


It it out of a Yamaha CD-1050 and has recently begun causing trouble.

I have modestly modded this CDP with the usual, straight forward mods, and while I was at it I cleaned the pickups lens (it was filthy) which resulted in the successfull playing of CD-R's.

I added some damping to the tray, and also to the clamp (very little, but enough to make a difference) with no adverse effects.

With the CDP re-assembled, things went along swimingly, apart from the tray 'clunking' when ejecting and retracting the tray. To combat this I lubed the ejecting gear and attempted to remedy the banging of the tray with some adjustments, but due to the way it's designed there isn't much of a cure for the 'clunking' sound when loading or ejecting.

I also re-applied grease to the clamp's spindle, which is simply a round bit of plastic that pivots on an embedded bearing.

While I was in there I applied some grease (precision gear grease) to the laser assembly's 'rails' and gears (the assembly is moved on the rails by a stepper motor using gears etc).

Now the device balks at track 1 on every disc, skipping and jumping erraticaly, and can hear the servo working overtime it appears, to read the TOC etc. Ejecting and re-seating the disc in the transport can sometimes help, but eventually it will begin skipping again anywhere on a disc.

I would be much appreciated for some insight and/or assistance to remedy this. I currently have the transport out and have disassembled the thing to give the rails, gears etc a thorough clean and re-lube.

I have read that car transmisison fluid is a good lubricant for the laser mech's guide rails? and I assume that the precision gear grease is adequate for the gears?

Thank you.
 
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Did it play DVD-R as shown on the picture ?? How special ;)

I think using grease for the gears is wrong because it played OK before you lubricated things. You should never apply grease to laser assembly's 'rails' and gears. Use a very tiny drop of light oil instead on the rods/rails ( make sure it does not harm plastics !!! ). Forget about lubricating plastic gears, it is not necessary and will make problems worse. Grease makes it difficult for the gears to move quickly and thus the mechanism will cause errors.

So clean the rods/rails with isopropyl alcohol and try it again with a light thin oil. Remove the grease form the gears that control the laser please. Be careful to use a cloth that does not leave fibers on the gears.

BTW what's the typenumber of the pickup ?
 
Hello Jean-paul.

Thank's for the hints, I shall give the whole transport a proper cleaning etc and see how it goes.

The pickup has two numbers on it, the first one is on the lens shroud and is TAOHS-JP3

An externally hosted image should be here but it was not working when we last tested it.


The other number on it looks like a part or serial number and is: A2A95100402 and underneath that number is B 53.2 and 134
 
Well I have completely pulled the transport mechanism apart. The plastic sprockets (cogs) that are used for the pickup were fairly grotty and the axles were loose, probably just from years of use but there was very little wear of the cogs or axles. So I gave them all a good clean and re-assembled them (with no grease). They are nice and tightly fixed with very little play or 'slop' but loose enough to spin freely, the mesh between the teeth is very good.

The stepper motor for the pickup is still in pretty good condition, a bit of a clean and re-attaching was all that needed, however the belt from the motor to the gears (thats how old this thing is folks, still uses belts! :eek:) is slightly fatigued (stretched) which could add to tracking innacuracy - more on this bit later.

I've cleaned the sliding 'rails' as jean-paul suggested, as well as the brass bushings on the pickup that actually slides on these rails and re-assembled. The only lubricant I had that was remotely suitable was some light teflon-based oil (from Radio Shack), and a drop on each rail had the laser pickup sliding very smoothly on the rails from one end to the other with extremely little resistance, this itself has got to be a vast improvement.

The pickup uses something similar to a 'rack and pinion' arrangement where the 'rack', a long straight piece of plastic with teeth along one side is attached to the actual pickup. This rack is actually two thin pieces one on top of the other and a spring is used between the two pieces as a tensioning device. This obviously provides for precision movement of the laser pickup. As the pinion gear rolls along the rack teeth there is the obvious side affect of play between the teeth which this method virtualy eliminates (Have I explanied this easily enough?).

I'm not sure what to do with the rubber belt here though, there doesn't appear to be any slippage, and after the good cleaning I gave the belt pulleys I think this is not an issue.

Unfortunately I had to leave the rebuild at that for now (work sucks :( ) but if anyone is interested I will happily continue to keep everyone involved in this rebuild. If nothing else it may be useful for anyone who wishes to attempt something similar. :)

Thanks jean-paul for your advice also. Oh and the DVD-R was in there for testing/storage only. :p
 
Success!!

After the thorough clean and rebuild of the transport mechanism, I am pleased to announce that the player is working again and has yet to miss, jump, skip or fault! :D

The pickup is by far in better condition than it has probably ever been and reads a discs TOC almost instantly. track seek is quick and precise and no longer makes any audible noise reading even CDR's.

Thanks for sharing your experience jean-paul, I would have been sad to have it die as this player sounds quite pleasant after the work I have done to it.

Though if anyone can still identify this CDM I would like to know.

Cheers,
 
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