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Troubleshooting CD Players

Tnx..
Service manual mention Sony test cd and "special" test circuit to perform adjustments... Is that critical.
Never worked on cd players
 
Oggioffshore said:
Tnx..
Service manual mention Sony test cd and "special" test circuit to perform adjustments... Is that critical.
Never worked on cd players
Click to expand...
Any commercially made CD will work.
The special circuit is only for adjusting the focus gain and tracking gain. Leave them alone and you won't need it.
For the Tracking Offset / Tracking Balance you will have to turn the tracking gain all the way down, so mark the position of the pot and return it to the same position.
Before adjusting, look at the RF waveform. Signal should be 1.5V p-p or laser power is low.
 
Hi. I picked up a Sony X111ES at at estate sale for $5. It rejects cds a few seconds after closing the drawer. Drawer also needs help opening at times. I did discover that I can get a cd to play if I insert it, hold drawer closed and set the player up on end. (See photo.) I'm assuming replacing the belt fix the disc rejection and allow it to play in normal position. Thoughts?

By the way, this unit sounds amazing. Smooth and detailed without harshness or brittleness. Tight, musical bass. Thanks.

GREG
 

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Hi Dr. Audio,

This is an amazing thread, but it’s 41 pages long. Perhaps my problem is solved somewhere, but it’s buried.

i’m not sure what’s going on with my Nakamichi OMS3A. It uses a KSS-123A laser. I can’t really see the cartridge move up or down when it attempts to load the disk. It’s difficult to see in there. And I certainly don’t see a red laser light when it’s trying to read…. Maybe it’s never getting in a position to read, maybe the laser has gone bad.

So the player used to work fine, then it would behave this way from time to time, now it won’t work at all. I thought perhaps the laser mechanism wasn’t getting power…. But more and more, I think the laser is just dead.

I have bought a new laser, but have not opened it yet. It was kind of expensive, so I’d like to change it only as a last resort.

I’m trying to share a video, hopefully this link works.
https://www.icloud.com/iclouddrive/0eavJFOYT6L0F5LI052dMA8Ww#IMG_1058

one thing that I wish I had captured better in my video was a whirling clicking sound that happens in between it’s turn attempts.
 
Since it spins the disc, that means it achieves focus lock, but it can't read data. The laser is probably bad.

kyledp said:
Hi Dr. Audio,

This is an amazing thread, but it’s 41 pages long. Perhaps my problem is solved somewhere, but it’s buried.

i’m not sure what’s going on with my Nakamichi OMS3A. It uses a KSS-123A laser. I can’t really see the cartridge move up or down when it attempts to load the disk. It’s difficult to see in there. And I certainly don’t see a red laser light when it’s trying to read…. Maybe it’s never getting in a position to read, maybe the laser has gone bad.

So the player used to work fine, then it would behave this way from time to time, now it won’t work at all. I thought perhaps the laser mechanism wasn’t getting power…. But more and more, I think the laser is just dead.

I have bought a new laser, but have not opened it yet. It was kind of expensive, so I’d like to change it only as a last resort.

I’m trying to share a video, hopefully this link works.
https://www.icloud.com/iclouddrive/0eavJFOYT6L0F5LI052dMA8Ww#IMG_1058

one thing that I wish I had captured better in my video was a whirling clicking sound that happens in between it’s turn attempts.
Click to expand...
 
kyledp said:
Thank you for confirming that dr*audio, that's exactly how I will proceed. I'll let y'all know how it turns out.
Click to expand...
There will be a solder blob on the new laser that must be removed. Wear a grounded antistatic wrist strap when you work on it!
 
Hello. I have a Nakamichi CD-4. It's developed a problem where upon loading a CD, it will spin for about a quarter turn, then nothing. The display shows track 1 as if it is ready to play, but none of the buttons other than the load/eject button do anything.

Suggestions where to start?
 
JASnyder said:
Hello. I have a Nakamichi CD-4. It's developed a problem where upon loading a CD, it will spin for about a quarter turn, then nothing. The display shows track 1 as if it is ready to play, but none of the buttons other than the load/eject button do anything.

Suggestions where to start?
Click to expand...
Does it make a sizzling sound when it stops turning? I haven't worked on one of these, not familiar with the behavior. Check the rf with a scope. Check the focus output to see if it's doing focus search.
 
Sorry to ask for old info but I can't find where there were posts about the more reliable old CD players. I thought I saw it 1 or 2 years ago but I don't see it. I think Phillips was one brand
 
parman said:
Sorry to ask for old info but I can't find where there were posts about the more reliable old CD players. I thought I saw it 1 or 2 years ago but I don't see it. I think Phillips was one brand
Click to expand...
There are no lasers available for Philips. Avoid them.
Onkyo, Sony, Adcom, and Denon used Sony lasers on many models, you have to Google the model# and "laser" to find out what laser it used. KSS150A has been replaced with KSS210A. KSS240A and KSS213 all available. BD Enterprises is a good source and also Liberty Electronics on ebay. I wouldn't buy them from anyone else.
 
dr*audio said:
Does it make a sizzling sound when it stops turning? I haven't worked on one of these, not familiar with the behavior. Check the rf with a scope. Check the focus output to see if it's doing focus search.
Click to expand...
It does not make a sizzling sound. I do not have a scope available to me at the moment so this may need to go on the shelf for a while.
 
JASnyder said:
It does not make a sizzling sound. I do not have a scope available to me at the moment so this may need to go on the shelf for a while.
Click to expand...
This uses a KSS-210A laser, which is probably bad. Liberty Electronics on ebay sells good ones. This has a Sony chipset but the microprocessor is different and the behavior is probably due to that. Normally if it achieves focus lock it will spin the disc, for at least a couple seconds while it reads the TOC. If it can't read TOC because the laser power is low it will stop spinning. Never saw a player that turns 1/4 turn and stops. You can try giving the disc a little push and see if it spins more. If so, the disc motor is bad. If not, the laser is probably bad.
 
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Hi Dogwan, did you ever get this resolved? I have the same unit, same problem.

dogwan said:
Nakamichi CD-4 here that I'd like to see if I can get working.

Not to be confused with the Nak "CD Player 4".

The "CD-4" was mentioned a couple times earlier in this thread and my symptoms are similar. I didn't see any resolution to those cases after reading through the whole thread.

Nice lady gave me this deck for free, not working. She said she took it in to a shop and was told it was "Not repairable". I suspect that they just really meant it's not worth the expense. So I thought I would just treat it as a learning exercise. It would be nice if I could revive it, but I am willing to cut bait too if it becomes a fools errand. I've tried to find the SM but no luck so far.

Looking inside it has all Nichicon caps, including a tone of the Green Muse's. Only a single AD1865 DAC chip. But at least it does have digital out capability.

So anyway, here goes. I am going to list out the symptoms and observations so far and see what y'all think. Especially you @dr*audio !
  • CD physically loads just fine. Drawer moves smoothly and transport moves into position both with, and without a disc.
  • Laser transport moves into home position (doesn't move back like a typical transport, but others with CD-4's noticed the same thing).
  • I did remove the PCB for access and cleaned the home/stop switch. No change.
  • Using my cell phone I can see the red laser light when I power the unit on. It goes out as expected when it doesn't load TOC/ recognize disc. (see pic attached)
  • When initialized laser lens does pop up and down once trying to focus. (it only does it once, not sure if this is normal, other transports I've seen it bounce a couple times trying to focus)
  • Pin 1 of C105 = ±1.9v an then fades after initialization.
  • With no disc inserted, initialization results in spindle motor rotates 7/8 to 1.5 rotations (as observed with a witness mark on top clamp)
    Note: there is a slight ssst, ssst, sound that appears to be top clamp rubbing due to lack of thickness of CD.
  • With disc inserted, initialization results in spindle motor rotates only 1/4 turn and it's pretty slow at that.
    Note: above mentioned ssst sound is absent. If I manually spin disc there is no indication of rubbing.
  • With transport assembly removed I applied 3v to spindle motor (Matsushita MDN-4RA3FTAS 3v motor) by connecting 2x AA batteries in series. Spindle motor spins freely and quietly. (but I did not measure current draw)
  • With transport assembly fully hooked up and initialized I measured voltage across spindle motor + and - terminals and it would spike to between 0.9 to 1.3v and immediately drop to zero. (am I just measuring voltage drop across motor here?)
    If I measured between positive terminal of motor to ground I get 0v.
So that's as far as I've gotten. I'm leaning towards thinking spindle motor is suspect? But I don't quite understand the logic sequences of startup, so it wouldn't surprise me if the laser failing were causing the spindle to not actually spin up.

Edit: I did try oiling the spindle motor and running for a minute or so on battery power to work the oil in. No difference to behavior.

I do have an old Tektronix scope and so far have mastered turning it on. I have more tenacity than actual electronics knowledge. But my mechanical abilities are pretty good. My old aeronautical engineer uncle used to tell me I was one of the most natural "Barnyard Engineers" he's met...LOL.
Click to expand...
 
dr*audio said:
There will be a solder blob on the new laser that must be removed. Wear a grounded antistatic wrist strap when you work on it!
Click to expand...

hi Dr, Audio, I’ve searched and searched for this solder blob by comparing the new unit with the old. I couldn’t find it. I even installed the new laser. The disc turns like it wants to begin, but ejects after spinning a few seconds. This is a different behavior than before. It turns at speed whereas before it started to spin several times.
 
kyledp said:
hi Dr, Audio, I’ve searched and searched for this solder blob by comparing the new unit with the old. I couldn’t find it. I even installed the new laser. The disc turns like it wants to begin, but ejects after spinning a few seconds. This is a different behavior than before. It turns at speed whereas before it started to spin several times.
Click to expand...
It's on the trace side of the little circuit board on the laser.
 
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