Troubleshooting CD Players

[WickedWillie]

Someone in my church has a Bose tabletop CD player/Radio. Inadvertently inserted the CD upside down...can't get the CD out by conventional means. Anything I need to be aware of in order to open this thing up for her and get her CD out?

Thanks in advance for any information.

 

[shigeto]

hello there,
I've just read this thread, trying to find an answer but I'm not so sure how to interpretate my CD Player behavior .

I have a Cambridge Audio 640C V2 unit and lately , randomly , while a CD is running , there are some moments (half of a second) when the player stop reading the CD (not skipping, just silence, without any error mesage, the track time dissapear and appear after the "magic moment" goes). I've made many tests, with different CD's ,in very good conditions with the same results.

I've opened the player case and I've watched the pickup lens movements .In that moments of silence , the lens is try to locate the "track" moving around .
Until now, I've disconected and cleaned the ribbon lens block, I've cleaned the lens surface and at this point I'm not so sure what can I do next.

Do you ever meet in your experiences this CD player behavior ? It's time to buy a new optical block ?
Thank you,

 

[dr*audio]

hello there,
I've just read this thread, trying to find an answer but I'm not so sure how to interpretate my CD Player behavior .

I have a Cambridge Audio 640C V2 unit and lately , randomly , while a CD is running , there are some moments (half of a second) when the player stop reading the CD (not skipping, just silence, without any error mesage, the track time dissapear and appear after the "magic moment" goes). I've made many tests, with different CD's ,in very good conditions with the same results.

I've opened the player case and I've watched the pickup lens movements .In that moments of silence , the lens is try to locate the "track" moving around .
Until now, I've disconected and cleaned the ribbon lens block, I've cleaned the lens surface and at this point I'm not so sure what can I do next.

Do you ever meet in your experiences this CD player behavior ? It's time to buy a new optical block ?
Thank you,

You would really need an oscilloscope to troubleshoot this. You need to look at the RF signal, tracking signal and focus signal to see which one is being lost. My guess, though is either the pickup is failing or the flat flexible cable to the pickup is failing. If you can take a high res macro photo of the mechanism, showing the laser, with the drawer open, I may be able to figure out who made it. If the laser has a little pc board on it, see if there is a part number on the board.

 

[mr.jones]

This thread should be a sticky!

 

[shigeto]

hello there,
@dr*audio, thank you for your fast answers .
Unfortunately I don't have an oscilloscope .
Regarding the type it's all clear , according to this list the mechanism is Sanyo SF-P101N 16 pin (not 15) cheap enough (15-20 $) to replace it with a new one. Also I can replace the ribbon cable too in order to eliminate the other possible fault cause.

But until then , I am thinking to another possible faulty reason , but I'm not so sure, maybe I'll try before I'll replace the optical block + mechanism. This fault can be cause by the suspension system ,or by the rubber strap ?

I've asked this because sometimes , when the tray is close , the door motor is trying to complete the operation running a few moments more after the CD door reach the final position inside the Player ...

I also have found and cleaned that 2 micro contacts that on/off the motor tray , also on /off the motor mechanism to lift up on play /going down on eject the optick block mechanism.

@mr.jones this is already a sticky thread thank you,

 

[dr*audio]

hello there,
@dr*audio, thank you for your fast answers .
Unfortunately I don't have an oscilloscope .
Regarding the type it's all clear , according to this list the mechanism is Sanyo SF-P101N 16 pin (not 15) cheap enough (15-20 $) to replace it with a new one. Also I can replace the ribbon cable too in order to eliminate the other possible fault cause.

But until then , I am thinking to another possible faulty reason , but I'm not so sure, maybe I'll try before I'll replace the optical block + mechanism. This fault can be cause by the suspension system ,or by the rubber strap ?

I've asked this because sometimes , when the tray is close , the door motor is trying to complete the operation running a few moments more after the CD door reach the final position inside the Player ...

I also have found and cleaned that 2 micro contacts that on/off the motor tray , also on /off the motor mechanism to lift up on play /going down on eject the optick block mechanism.

@mr.jones this is already a sticky thread thank you,

Be wary of buying laser pickups from E-Bay sellers. You may be getting a counterfeit part. Donberg Electronics claims to have one, that one is probably genuine. Better buy it while you can. No other reliable seller I know of has this part.
The loading belt should be replaced but I don't think that is the problem since it is already playing then fails. If it was the belt it would not go into play until it is fully loaded.

 

[shigeto]

Hello there,
hmm, there is a price difference , it sounds too good to be true , U're right
Thanks, I'll be carefull.

I've watched all day the rubber belt role in the mechanism, again, u're right dr. , the belt even if it's a little deformed (the Player was unused for several months) is still doing his job.

LE: I've unplugged the other end of the ribbon that goes to the electonic board and cleaned with Kontakt 61 .There was some dirt (oxide?) hope will be fine ... still testing.

thank you for your time and support.
I appreciate it.

PS: funny, in my car there is a CD player ... still reading since 2006 every kind of CD's without skipping or coughing at +30*C / -10*C also I have a portable Phillips Player that works like a charm no matter what ) This CA 640C V2, carefully used, messing around P

LE update 05.11 : it looks like the ribbon was the fault cause .The player read smoothly again, I've listened already a few CD's from beginning to the end, then shuffle , etc . The problem is gone, hope for good
Thanks a lot !! Indeed @phatster , this thread is priceless

 

[dr*audio]

Hello there,
hmm, there is a price difference , it sounds too good to be true , U're right
Thanks, I'll be carefull.

I've watched all day the rubber belt role in the mechanism, again, u're right dr. , the belt even if it's a little deformed (the Player was unused for several months) is still doing his job.

LE: I've unplugged the other end of the ribbon that goes to the electonic board and cleaned with Kontakt 61 .There was some dirt (oxide?) hope will be fine ... still testing.

thank you for your time and support.
I appreciate it.

PS: funny, in my car there is a CD player ... still reading since 2006 every kind of CD's without skipping or coughing at +30*C / -10*C also I have a portable Phillips Player that works like a charm no matter what ) This CA 640C V2, carefully used, messing around P

All lasers are not created equal. Some last much longer than others.

 

[phatster]

This thread is very instructional and hilarious at the same time.This is priceless material! Thanks to everyone.

 

[dr*audio]

This thread is very instructional and hilarious at the same time.This is priceless material! Thanks to everyone.

I must have missed the funny part...:scratch2:

 

[phatster]

Your straight forward no BS retorts are just what I like to hear.This is so uncommon in my world.This meant to be a compliment!

 

[dr*audio]

Your straight forward no BS retorts are just what I like to hear.This is so uncommon in my world.This meant to be a compliment!

Thanks!

 

[damager]

Thanks!

Ok HERE's a question for you Dr. Audio...

how the HELL do you KNOW SO MUCH about repairing freakin CD PLAYERS!??!?!?!?!

:scratch2:

Most impressive. Using your original post I'm about to begin a laser swap on my Nakamichi CD-4 that is not picking up discs. I had my buddy replace the laser once last year, and it worked for about 1 -2 weeks. Then went dead again. I'm wondering if I got a crap laser. It was cheap enough, so I suppose i'll try and swap it out to see if that was indeed the case.

If the thing DID indeed work for a week, would you say that's what my problem was? of coruse, i realize this is difficult to diagnose without even seeing the thing and just going on my story.

One question... I notice that there's a grease type material on the gears. Obviously i'll have to replace this grease. What kind of grease is this? and can you recommend a comparable / compatibly grease?

 

[dr*audio]

Ok HERE's a question for you Dr. Audio...

how the HELL do you KNOW SO MUCH about repairing freakin CD PLAYERS!??!?!?!?!

:scratch2:

Most impressive. Using your original post I'm about to begin a laser swap on my Nakamichi CD-4 that is not picking up discs. I had my buddy replace the laser once last year, and it worked for about 1 -2 weeks. Then went dead again. I'm wondering if I got a crap laser. It was cheap enough, so I suppose i'll try and swap it out to see if that was indeed the case.

If the thing DID indeed work for a week, would you say that's what my problem was? of coruse, i realize this is difficult to diagnose without even seeing the thing and just going on my story.

One question... I notice that there's a grease type material on the gears. Obviously i'll have to replace this grease. What kind of grease is this? and can you recommend a comparable / compatibly grease?

1. I worked for 6 years at Fretter as their Audio Service Tech. I repaired many hundreds of Cd players.
2. If you follow the troubleshooting guide and it looks like the laser is bad, you probably got a cheap Chinese knockoff. I had one of these go bad after about a month. don't buy lasers from Electronix.
3. If the grease isn't thick or dirty there is no reason to replace it. If you do, use a light weight lithium grease. Dupont makes a nice on in a spray can, with Teflon in it. Lowes sells it.

 

[damager]

1. I worked for 6 years at Fretter as their Audio Service Tech. I repaired many hundreds of Cd players.
2. If you follow the troubleshooting guide and it looks like the laser is bad, you probably got a cheap Chinese knockoff. I had one of these go bad after about a month. don't buy lasers from Electronix.
3. If the grease isn't thick or dirty there is no reason to replace it. If you do, use a light weight lithium grease. Dupont makes a nice on in a spray can, with Teflon in it. Lowes sells it.

I carefully read through your original instructional post. Thanks ever so much for the invaluable info. As per your instructions, I observed the motor upon powering up the CDP. the motor moves towards the front of the unit, maybe a couple of mil's, then stops. Doesn't move after that. But when I power down, the thing moves back to where it was originally. So that suggests a dirty switch according to your post.

I currently have the CDP apart, and am trying to get at that switch to clean it out and see if that helps before I swap out the pickup. (by the by, i mistakenly bought a KSS-212B instead of an A, I understand these ARE interchangeable but have differing voltages? either way, i'm not going to use it and send it back). Just having trouble getting at the switch is all. But I'll get it!

 

[dr*audio]

I carefully read through your original instructional post. Thanks ever so much for the invaluable info. As per your instructions, I observed the motor upon powering up the CDP. the motor moves towards the front of the unit, maybe a couple of mil's, then stops. Doesn't move after that. But when I power down, the thing moves back to where it was originally. So that suggests a dirty switch according to your post.

I currently have the CDP apart, and am trying to get at that switch to clean it out and see if that helps before I swap out the pickup. (by the by, i mistakenly bought a KSS-212B instead of an A, I understand these ARE interchangeable but have differing voltages? either way, i'm not going to use it and send it back). Just having trouble getting at the switch is all. But I'll get it!

Sony B lasers are lower voltage, for boombaxes and are NOT interchangeable with the A part.
Does the lens move up and down? (Focus search,) If it doesn't do focus search, the home switch is dirty or bad.

 

[damager]

Sony B lasers are lower voltage, for boombaxes and are NOT interchangeable with the A part.
Does the lens move up and down? (Focus search,) If it doesn't do focus search, the home switch is dirty or bad.

OHHHHH boy oh boy.... I got a great tale to tell here.

Okay, So I got the thing open as I said, got to the switch (had to remove the motor board as you said in your original post). and cleaned her out using the 600 grit sandpaper, gentle push back and forth on each of the two contacts. gave it a blast of contact cleaner as well. Put the cover back on. At this time I should have done a quick continuity test on the motor board to test out the switch, but i neglected to think of that. Put the motor board back on and reassembled and gave it a whirl hoping that would do it (WITHOUT putting the new laser pickup in). Nothing. Did the exact same routine.

SO! as I'm looking at the damn laser pickup in the unit (don't worry, didn't look directly at the lense!!) I notice the number on it: KSS-210B. This is the wrong motor, is it not?? That means that the guy who fixed this prior installed the WRONG DAMN LASER PICKUP into this thing. I then looked at my new one that I didn't install yet: KSS-210A. i DID BUY THE RIGHT ONE. Super excited at this point, i carefully swapped out the pickup and fired her up.

NOTHING! :dammit: Although THIS time, the pickup didn't move at ALL. Well, except for the initial startup when it moved back into position against the switch. After that, now upon power up the pickup doesn't move pretty much AT ALL.

Dr*Audio, if you do have the time, i'd LOVE your opinion on this. I'm assuming the worst, that having this incorrect pickup in the unit mighta f'd something royally somewhere. Keep in mind that the player DID WORK with this incorrect pickup for a time, but $h1t the bed after a week or two.

What should be my next course of action? In the meantime i'm going to take out the motor board again and test for continuity just to be sure that the switch isn't screwing up or something. OH!! Almost forgot: the lens does NOT move up and and down at all far as I can tell.

 

[dr*audio]

OHHHHH boy oh boy.... I got a great tale to tell here.

Okay, So I got the thing open as I said, got to the switch (had to remove the motor board as you said in your original post). and cleaned her out using the 600 grit sandpaper, gentle push back and forth on each of the two contacts. gave it a blast of contact cleaner as well. Put the cover back on. At this time I should have done a quick continuity test on the motor board to test out the switch, but i neglected to think of that. Put the motor board back on and reassembled and gave it a whirl hoping that would do it (WITHOUT putting the new laser pickup in). Nothing. Did the exact same routine.

SO! as I'm looking at the damn laser pickup in the unit (don't worry, didn't look directly at the lense!!) I notice the number on it: KSS-210B. This is the wrong motor, is it not?? That means that the guy who fixed this prior installed the WRONG DAMN LASER PICKUP into this thing. I then looked at my new one that I didn't install yet: KSS-210A. i DID BUY THE RIGHT ONE. Super excited at this point, i carefully swapped out the pickup and fired her up.

NOTHING! :dammit: Although THIS time, the pickup didn't move at ALL. Well, except for the initial startup when it moved back into position against the switch. After that, now upon power up the pickup doesn't move pretty much AT ALL.

Dr*Audio, if you do have the time, i'd LOVE your opinion on this. I'm assuming the worst, that having this incorrect pickup in the unit mighta f'd something royally somewhere. Keep in mind that the player DID WORK with this incorrect pickup for a time, but $h1t the bed after a week or two.

What should be my next course of action? In the meantime i'm going to take out the motor board again and test for continuity just to be sure that the switch isn't screwing up or something. OH!! Almost forgot: the lens does NOT move up and and down at all far as I can tell.

On the circuit board on the new pickup there are 2 pads with a blob of solder across them to protect the laser from static electricity. The solder short must be removed when you install the new pickup.

 

[damager]

On the circuit board on the new pickup there are 2 pads with a blob of solder across them to protect the laser from static electricity. The solder short must be removed when you install the new pickup.

Took off the solder blob using some solder wick. fired her up, NOTHING. :thumbsdn:

Although, one thing different i did notice is that the pickup lens DOES move now upon power-up. although its not a gentle movement, it kinna jumps. kinna like someone flicked it with their finger or something.

But still nothing as far as recognizing a disc. The pickup still does it's routine of moving all the way towards the front of the unit til it cannot go anymore. But one thing i DID do was test that motor board AND switch for continuity. The switch DOES seem to be doing it's job, as when the pickup is moved against it, there is now continuity between the two sides. And conversely, when it's moved away there's none.

So, I've ruled out the switch, and the pickup (hopefully. Unless I got a crap one from the place I ordered). Referring back to your original post there, the pickup is still not finding it's home position. If that's the case, then i guess I don't know where that leaves me. dammit. If I am at some stage where I have to bust out a scope, i suppose that's that as not only do I not have one, but I don't even know anyone that does.

whaddya think?

 

[dr*audio]

Took off the solder blob using some solder wick. fired her up, NOTHING. :thumbsdn:

Although, one thing different i did notice is that the pickup lens DOES move now upon power-up. although its not a gentle movement, it kinna jumps. kinna like someone flicked it with their finger or something.

But still nothing as far as recognizing a disc. The pickup still does it's routine of moving all the way towards the front of the unit til it cannot go anymore. But one thing i DID do was test that motor board AND switch for continuity. The switch DOES seem to be doing it's job, as when the pickup is moved against it, there is now continuity between the two sides. And conversely, when it's moved away there's none.

So, I've ruled out the switch, and the pickup (hopefully. Unless I got a crap one from the place I ordered). Referring back to your original post there, the pickup is still not finding it's home position. If that's the case, then i guess I don't know where that leaves me. dammit. If I am at some stage where I have to bust out a scope, i suppose that's that as not only do I not have one, but I don't even know anyone that does.

whaddya think?

The pickup sounds like it is in the home position; otherwise it would not do focus search. If the disc doesn't start spinning after focus search and you don't hear a sizzling sound (meaning a bad disc motor) the pickup or the pickup wires is bad, or bad power supply to the laser. There may be a resistor or fuse in series with the laser supply on the main board that opened when you ran it with the solder short in place.