CD player does not spin

[madan1]

Hi everyone. Just got my hands on an onkyo c-705tx.
First does anyone has service manual for this?

So I checked the power lines and have few suspicious
-10.8 ( should be -10 )
+9.7 ( should be +10 )
+5
+7.05 ( should be 7.5 )
The power caps visually are fine.
The lens looks like a little bit blurish to me, but last time I used a cd player was long time ago, so I've forgotten what a good lens looks like ( see image ).
When a cd is placed in the tray, it will not spin. On empty tray I can see that the laser is working ( on my phone camera, not looking straight at it ).
The spindle and laser pickup motors both read 11.3 ohms and I can confirm that the laser pickup motor works fine.
The laser pickup is kss213c. I turned the pot to boost the output, but still the cd does not spin.
I do not see anything there to detect if there is a cd, so I guess it is the laser pickup job?
What do you think.. is it only the laser pickup which has failed or there is something else?

[petehall347]

Re: CD player does not spin

spin cd manually at the point it would normally spin ..see if it keeps spinning
also see if it tries to spin at all like if it just jumps a little or not when in normal use .

[petehall347]

Re: CD player does not spin

another thing if laser on rails move it so its at edge of cd and see if it resets to centre .
and try different cd.s ... pre recorded bought ones are best .

[madan1]

Re: CD player does not spin

spin cd manually at the point it would normally spin ..see if it keeps spinning
also see if it tries to spin at all like if it just jumps a little or not when in normal use .

No, it will not continue spinning and not even tries to start.

another thing if laser on rails move it so its at edge of cd and see if it resets to centre .
and try different cd.s ... pre recorded bought ones are best .

Yep, did this - that's how I determined that it was working

well, I will try with several other cds

[jiroy]

Re: CD player does not spin

I think those voltages are within the acceptable norms . Cleaning the laser lens with a water wet cotton swap , blowing the dust and greasing the supporting rails , changing the Dynamo belt for a better loading , using new and good CDs labels is some of many problems that might keep a CD player from sinning right ..

But in the end , one should consider that most of the CD players laser's life expectancy evolve around 700 hours ..

Just for fun : L.A.S.E.R. == Light amplification by stimulated emission of radiation .

[madan1]

Re: CD player does not spin

I just changed the laser pickup with a new one with a nice transparent lens and.... nothing.
The spindle motor works fine when powered with a single AAA battery, but there is no voltage coming from the main board when the tray is inserted.

So here is the main question for now - when does the spindle motor start?
A - when the tray is inserted and before the laser pickup reads the disc
B - after the laser has recognized the disc
( or does the laser pickup need the disc to be spinned to recognize it )

Basically I need a starting point for troubleshooting - the laser pickup part or the motor part.

[petehall347]

Re: CD player does not spin

did you remove solder blob from new laser unit ?

[madan1]

Re: CD player does not spin

did you remove solder blob from new laser unit ?

hmmm no.. where is it?
That's my first encounter with CD equipment and I'm pretty much blind here

[petehall347]

Re: CD player does not spin

new laser units more often than not have a solder blob to short it out for transportation .. look up the laser id number on the internet .

[madan1]

Re: CD player does not spin

I think I found it.. at least there is a solder blob which shortens two of the pins on the new unit and is missing on the old one.
Well.. just turned on the solder iron, is I guess in 5 minutes I will have more information .
In the part shop I asked about plug-n-play laser pickup and they did not mention anything about that.

[madan1]

Re: CD player does not spin

Aaand there we go

I removed the blob and now it seems to be working ( I have not tested the sound output yet ).
petehall347 thanks for the tip
Indeed I got the unit without the box ( the only one left ) and I guess on the box were the instructions.
Thanks everyone!

[petehall347]

Re: CD player does not spin

nice one ..i like the easy ones ...

[madan1]

Re: CD player does not spin

Still pity it does not want to play my Fatboy Slim "halfway b/n the gutter and the stars" cd . I guess 10+ years in the binder has taken its toll.
I tried playing with the pickup potentiometer, but with no success. Got it back to its pre-setted position and in the next days I will test it with more CDs to find the best value.
On the mainboard there are two more pots - focus offset and focus gain. In the service manual of a 30+ old pioneer cd player those were to be set with a two channel scope and a signal generator ( which I do not have ). Is there any point tweaking them without that extra equipment or I might just kill it for good?

[petehall347]

Re: CD player does not spin

do not tweak anything .. put the laser back to exact setting it was at ..i hope you measured resistance of adjusting pot ...

[madan1]

Re: CD player does not spin

Yeah, I guess I'll leave it like that. I found some audio cds and the not recognized ones are less than 10% which given their condition is really acceptable.

i hope you measured resistance of adjusting pot ...

of course... not
I just took a nice photo before installing it and used it for visual reference. From what I've read, if the current is boosted, it will reduce the life of the laser diode. This particular laser pickup is asscheap so even frying the diode does not worry me at all. Of course if it was an expensive unit I never would do such a sloppy job.

By the way, recently a friend of mine asked me to get him a cheap CD player... so I bought him a non-working 30+ year old YAMAHA which turned out to has decayed drive belts.
Anyway, I just wanted to say that the 30 year old yamaha sounds way better than this onkyo!

edit: the 30 year old cd player is Yamaha not pioneer!

[Agent24]

Re: CD player does not spin

No wonder it didn't go before, that original lens was ruined. I've seen worse, but that one was definitely bad.

https://www.repairfaq.org/sam/cdfaq.htm may help. Lots of info there on adjustment and getting the right laser setting.

That said, if it was brand new and of high quality (you didn't buy some cheap knockoff or second-hand one from Aliexpress, did you?) then maybe there is a fault in the drive circuitry or power supply instead.

[madan1]

Re: CD player does not spin

No wonder it didn't go before, that original lens was ruined. I've seen worse, but that one was definitely bad.

https://www.repairfaq.org/sam/cdfaq.htm may help. Lots of info there on adjustment and getting the right laser setting.

That said, if it was brand new and of high quality (you didn't buy some cheap knockoff or second-hand one from Aliexpress, did you?) then maybe there is a fault in the drive circuitry or power supply instead.

I guess there has been some kind of a chemical reaction which caused the lens to blur this way.. at least this is what I've seen to happen to plastics affected by certain alcohols.
The link is interesting, but I'll try to stay away from CD players in the future .. kinda not my thing .
I got the new pickup from the local electronic parts store and honestly - I have no idea about its origin. I got it without box ( last unit, box lost ) and visually looks fine.