Troubleshooting CD Players

[kyledp]

Not finding it…. I’m including 3 photos. Using the dead laser as an example of where this blob will be, I don’t see anything on the new one that’s not present on the dead one.

I suspect my laser is a refurbished one. I bought it on Amazon.

by the way, I really appreciate all your advice on this…

 

[classyharlan]

Sony CDP-203

The unit doesn't react when powered on and the front panel does not display. Checking the main board with a multimeter, the various points labeled as 12V read 12V as they should but the 5V and 10V points are non responsive (i.e. reading zero). I don't know how to troubleshoot any further. (Previously the sled motor did react slightly on power on but that stopped soon after.)

 

[dr*audio]

Not finding it…. I’m including 3 photos. Using the dead laser as an example of where this blob will be, I don’t see anything on the new one that’s not present on the dead one.

I suspect my laser is a refurbished one. I bought it on Amazon.

by the way, I really appreciate all your advice on this…

The KSS-123A hasn't been produced in years. I am sure it would have had a solder blob but I don't recall where it was. If it spins it is probably achieving focus lock but the laser output is too low to read the TOC. Do you have a scope?

 

[dr*audio]

Sony CDP-203

The unit doesn't react when powered on and the front panel does not display. Checking the main board with a multimeter, the various points labeled as 12V read 12V as they should but the 5V and 10V points are non responsive (i.e. reading zero). I don't know how to troubleshoot any further. (Previously the sled motor did react slightly on power on but that stopped soon after.)

Follow through the schematic and check the 10V supply. Sony used fuses they called IC Protectors, they can look like a small black transistor with only 2 legs. They go bad all the time. One may be open.

 

[classyharlan]

Sorry in advance for a confusing explanation here. There are two places where it goes capacitor A → regulator → capacitor B with seemingly no other components becoming involved. For both, the voltage across capacitor A matches the schematic, but across capacitor B does not (for one case C904 it's 0V and the other C903 it's 2.5ish V).

For C904, the voltage from its capacitor A (C902) to ground of its regulator (IC902) is 0, and for the C903 case from its capacitor A (C901) to its regulator (IC901) ground is 12V.

Also the voltages across either regulator from ground pin to either other pin is at or near 0V.

I had working exact replacements for the regulators so I swapped those out but the symptoms did not change.

I put the suspicious regulators in the deck from which I got the working replacements, and now that deck doesn't work, so I guess the the regulators were in fact bad, but it seems there are also other problems remaining.

 

[JASnyder]

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.

I replaced the laser yesterday - $20 from Liberty so I figured why not - same exact behavior, am getting a beam. I also tried helping the motor a bit, no effect.

I replied yesterday from my email inbox but the reply never posted.

 

[dr*audio]

I replaced the laser yesterday - $20 from Liberty so I figured why not - same exact behavior, am getting a beam. I also tried helping the motor a bit, no effect.

I replied yesterday from my email inbox but the reply never posted.

You did remove the solder blob on the laser pcb?

 

[JASnyder]

You did remove the solder blob on the laser pcb?

Not at first but went back and did that after I realized that I missed that step.

 

[dr*audio]

Sorry in advance for a confusing explanation here. There are two places where it goes capacitor A → regulator → capacitor B with seemingly no other components becoming involved. For both, the voltage across capacitor A matches the schematic, but across capacitor B does not (for one case C904 it's 0V and the other C903 it's 2.5ish V).

For C904, the voltage from its capacitor A (C902) to ground of its regulator (IC902) is 0, and for the C903 case from its capacitor A (C901) to its regulator (IC901) ground is 12V.

Also the voltages across either regulator from ground pin to either other pin is at or near 0V.

I had working exact replacements for the regulators so I swapped those out but the symptoms did not change.

I put the suspicious regulators in the deck from which I got the working replacements, and now that deck doesn't work, so I guess the the regulators were in fact bad, but it seems there are also other problems remaining.

View attachment 2725896 View attachment 2725897

Check PS901 and PS902, they are IC protector fuses.

 

[dr*audio]

Not at first but went back and did that after I realized that I missed that step.

Did that make a difference?
At this point you need to look at FOK and RF with a scope to see if it's getting Focus OK and if it has RF signal of 1.5V p-p.

 

[kyledp]

The KSS-123A hasn't been produced in years. I am sure it would have had a solder blob but I don't recall where it was. If it spins it is probably achieving focus lock but the laser output is too low to read the TOC. Do you have a scope?

Hi Dr. Audio,
No, I do not have a scope. And I’m not sure where I’d make any adjustments on this head to increase the output…

 

[classyharlan]

Check PS901 and PS902, they are IC protector fuses.

That was it. But there is one more issue...

I got the replacement regulators out of a CDP-55. So I thought I would just get the IC protectors out of the 55 as well because, as with the regulators, the service manuals for each deck lists the same component being used. However, in the 55 where the service manual lists that there should be IC protectors, there were only jumper wires. I removed the jumper wires from the 55 and put them in the 203 and turned on the 203 and the front panel lit up, but since the service manual says the IC protector is "critical for safety, replace only with part number specified", out of fear I turned it off again after just a few seconds.

1) Is it feasible that Sony would have originally put jumpers in place of the protectors in the CDP-55 in spite of what the service manual says?
2) Is it a real safety risk to use jumpers in place of the protectors in the 203?

I had used the CDP-55 for some time prior to this with no noticeable signs of being about to start on fire or getting hot, etc, and that was with the jumper cables in place of the protectors.

 

[JASnyder]

Did that make a difference?
At this point you need to look at FOK and RF with a scope to see if it's getting Focus OK and if it has RF signal of 1.5V p-p.

No difference. Am working on getting a scope, will pick this back up then. Thanks!

 

[dogwan]

Hi Dogwan, did you ever get this resolved? I have the same unit, same problem.

Not yet. I'm gonna order a laser here soon. One problem I see is that I can't quite figure out how to get the laser out of the carriage. I figured out how to remove the assembly well enough. But usually there is a release to pop the guide bar out, and then it's easy to slide the laser out. On this Nak the plastic bits that hold the guide rail look pressed in and fragile. Will report back when I dig a little deeper.

Also, a helpful hint as a newb here in the forums. If you put an ampersand in front of someone's user name (no space) it will ping them that they were mentioned in a thread.

Like this @JASnyder

I only stumbled on your question because I was catching up on this thread.

 

[dr*audio]

Not yet. I'm gonna order a laser here soon. One problem I see is that I can't quite figure out how to get the laser out of the carriage. I figured out how to remove the assembly well enough. But usually there is a release to pop the guide bar out, and then it's easy to slide the laser out. On this Nak the plastic bits that hold the guide rail look pressed in and fragile. Will report back when I dig a little deeper.

Also, a helpful hint as a newb here in the forums. If you put an ampersand in front of someone's user name (no space) it will ping them that they were mentioned in a thread.

Like this @JASnyder

I only stumbled on your question because I was catching up on this thread.

Post a good photo of the mounts for the slide post and I will advise. I am pretty sure it's a Sony mech.

 

[dr*audio]

That was it. But there is one more issue...

I got the replacement regulators out of a CDP-55. So I thought I would just get the IC protectors out of the 55 as well because, as with the regulators, the service manuals for each deck lists the same component being used. However, in the 55 where the service manual lists that there should be IC protectors, there were only jumper wires. I removed the jumper wires from the 55 and put them in the 203 and turned on the 203 and the front panel lit up, but since the service manual says the IC protector is "critical for safety, replace only with part number specified", out of fear I turned it off again after just a few seconds.

1) Is it feasible that Sony would have originally put jumpers in place of the protectors in the CDP-55 in spite of what the service manual says?
2) Is it a real safety risk to use jumpers in place of the protectors in the 203?

I had used the CDP-55 for some time prior to this with no noticeable signs of being about to start on fire or getting hot, etc, and that was with the jumper cables in place of the protectors.

If no one has worked on it before, Sony may have used this board on more than one model, and this model may have fuses located elsewhere that provide the protection. It is unlikely Sony would bypass the ICPs at the factory.
You may be able to find these NTE replacements.
https://www.nteinc.com/Web_pgs/icp.html

 

[classyharlan]

Is an ICP the same thing as a radial lead fuse?

 

[JASnyder]

Post a good photo of the mounts for the slide post and I will advise. I am pretty sure it's a Sony mech.

I scratched my head on that too. The bar slides toward the front of the carriage, there is a little latch that needs to be moved out of the way to allow it to clear the other mount, once clear you can pull it up and out. The 'plastic bits' do not get removed as part of this.

 

[dr*audio]

Is an ICP the same thing as a radial lead fuse?

A radial lead fuse will work if you get the same current value.

 

[decomo]

Awesome thread. I found this thread and began reading through pages.

Based on 1st page guide, I checked the mechanism with and without cd loaded and found that drawer open/close properly but the mechanism does not rise up to the play position. It comes up half way up so does not fully touch the CD.

Is it rubber belt worn out or can it be something else? Any guide would be hugely appreciated. Thank you.