Yamaha cd player spindle problem??

Try electrically disconnecting the motor (cut trace maybe) and running it, the motor in isolation, from a bench power supply to see if its a bearing problem. Only low voltage, 1 to 2volts at most usually

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

"N Cook" wrote in news:esjet1$dgr$ snipped-for-privacy@inews.gazeta.pl:

I did try running the motor from a low voltage and it ran okay but maybe I should let it run for 30min or so and see what happens???

TJB

They had problems with shorted brushes on those motors...

Mark Z.

"Mark D. Zacharias" wrote in news:IQcHh.5628$ snipped-for-privacy@newssvr22.news.prodigy.net:

Is the problem I described above a symptom of shorted brushes. I originally though it may be an overheating problem. Are there any other faults which could manifest themselves as described?

Is it possible to clean/repair these motors or do you simply just go and buy another one?

Thanks for the help so far TJB

The problem is removing the interference fit platter from the spindle without deforming the platter or if replacing the motor messing up the internal contact fingers by indirectly pulling at the spindle as well as original problem.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

The motor can be checked with an ohmmeter at a low ohms range setting, while SLOWLY rotating the motor. It should normally read 10 to 12 ohms or so. The reading will vary while turning, but should not be short-circuit or open at any one spot in it's rotation.

It is often possible to clear the short using an aerosol cleaner / lubricant with a pinpoint applicator, sprayed through the slits at the bottom, aimed at the brushes, while rotating manually, alternating with blowing it out with a compressor. It's usually necessary to repeat several times before the short clears. Blow out the excess cleaner with the compressor. You really need to understand the construction of small motors so you can "aim" the cleaner at the brushes.

Mark Z.

See:

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"Mark D. Zacharias" wrote in news:3BxHh.5755$ snipped-for-privacy@newssvr22.news.prodigy.net:

Thanks, I will try the motor rotation test and see what happens. Any thing else worth checking??

Thanks TJB

Sam Goldwasser wrote in news: snipped-for-privacy@blue.seas.upenn.edu:

Great repair faq!

Thanks TJB

TJB wrote in news:Xns98EDC44D7F024IDWhatID@203.16.214.243:

I measured the spindle motor resistance, it varied between 3 and 5 ohms. Normal??? Doesn't seem to have any slop in the bearing, but I put a very small drop of machine oil on it anyway.

I also noticed another possible problem with this deck: the clearance from the bottom of a cd in the holder to a plastic locating pin which pushes through a slot in the turntable is very very small. Possibly the spindle platter height is to low? There is a remote chance of a cd rubbing on this pin as it is playing.

Anyone have a value from the correct platter height? I measured from the chassis to the very start of the black plastic platter at 8.3mm, oops I probably should have measured to the flange where a cd would sit.

Anyway can anyone let me know what the platter height measurement should be : I guess that would be from where a cd sits to the chassis??

Thanks TJB

I'm almost certain the 3 to 5 ohms is too low. Spindle height is not standarized from model to model, but I believe it needs to be about 2 to 3 mm clearance from the pickup lens to the underside of the disc.

Mark Z.

That motor is supposed to slow down as the disk gets further done . All cd players do that . It takes a pretty free spining motor to run right at such low speeds . Put a drop of oil at the top bushing . I have had some luck running the motor isolated like already mentioned but using 6 or 9 volts to blow the carbon out of it so to speak ... that may or may not last . New motors are cheap

I agree that 3 to 5 ohms sounds low. Try this quick test: Disconnect the motor from the CD player and run it for a few seconds *only* at

8 or 10 V. This may blow out some of the crud but shouldn't damage an otherwise healthy motor. Then retest and report back. :)

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Repair | Main Table of Contents:

+Lasers | Sam's Laser FAQ: | Mirror Sites:

Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs.

snipped-for-privacy@webtv.net (Ken G.) wrote in news:18574-45F42E17-381@storefull-

3237.bay.webtv.net:

Unfortunately the motor was slowing down too much and the audio was breaking up horribly and then the motor would eventually stop.

I will probably replace the motor

Thanks TJB

Sam Goldwasser wrote in news: snipped-for-privacy@blue.seas.upenn.edu:

Pickup lense seems to be around 2mm, its that damn turntable locating pin (don't know why is has to be sooo big) that seems to close for comfort.

Tried it for a few secs at a higher voltage; the motor still measures around 3-5 ohms turning it slowly by hand. maybe I should just change it. Seems simple enough the platter is just a tight fit and should just pull straight off.

Thanks

TJB

TJB wrote in news:Xns98F19793B15AIDWhatID@203.16.214.243:

Looking at a replacement motor. The original is RF-310T-11400. The only motor I have found readily available is an RF-310. Is there any difference between the RF310 and the RF310T ??

Also avalable is a MDN4RA, looks like that is also the same physical size. Not sure if its suitable as there doesn't seem to be much info on any of these motors.

Thanks TJB

Try to get the exact same motor number. The different model suffixes often relate to the length of the motor spindle (shaft).

Carefully measure the spindle platter height before you remove it. Also, be aware that you won't likely be able to get it installed on the new motor "quite" true, meaning that you will probably have some spindle motor wobble after the new motor is installed. Shouldn't really be a problem, but I thought it should be mentioned...

Mark Z.

Pioneer cd assemblies have a little 'break off' U shaped turntable height gauge moulded onto the plastic frame, maybe yours has something similar

Ron(UK)

--
Lune Valley Audio
Public Address Systems

"Mark D. Zacharias" wrote in news:%cbJh.2776$ snipped-for-privacy@newssvr29.news.prodigy.net:

Mark, this may be a dumb question but I am going to ask anyway. Why would putting the platter onto a new motor cause any more wobble than with the current motor??? It has one of those pressed on plastic platters and assuming I don't bend the spindle.

TJB