Troubleshooting CD Players

[Ullar]

Thanks! I finally managed to reassemble my hifi system after relocating, the CD player is badly missed!
No, it won't move at all. Maybe I'm missing some switch other than the IN switch?
I'd expect the voltage on the motor to change even with bad capacitors, or am I wrong?

If you switch the player on the sled has to move to the center of the disc and pick-up should move up and down trying to focus.
It can be anything in sled drive circuity. I assume you have a service manual and have tested for voltages?

 

[McPint]

If you switch the player on the sled has to move to the center of the disc and pick-up should move up and down trying to focus.
It can be anything in sled drive circuity. I assume you have a service manual and have tested for voltages?

None of that happens.
Yes, I do have a service manual, I'll see if I can find any hint checking the voltages. Thanks for the suggestion.

 

[penmarker]

I have a Roksan Caspian MK1 CD player with a sanyo SF-90 laser and same internals like the CEC CD2100.
Tray loads fine but it doesn't read CD. The laser doesn't bob up and down, no movement from the laser.
Cleaned lens with alcohol and q tip but no response.

**Added: wires are fine because previously when the board was tested I didn't plug in all the connections so the laser and disc motor jittered a little.

Can anyone point me to the right direction?

 

[Ullar]

I have a Roksan Caspian MK1 CD player with a sanyo SF-90 laser and same internals like the CEC CD2100.
Tray loads fine but it doesn't read CD. The laser doesn't bob up and down, no movement from the laser.
Cleaned lens with alcohol and q tip but no response.

**Added: wires are fine because previously when the board was tested I didn't plug in all the connections so the laser and disc motor jittered a little.

Can anyone point me to the right direction?

That's what dr*audio suggested: If the lens doesn't move after the pickup finds home, either the pickup is bad or the cable for the pickup is broken, or the drive IC is bad, or there is a power supply problem. Some players have IC protectors that look like transistors with only 2 leads. They go open.

 

[McPint]

If you switch the player on the sled has to move to the center of the disc and pick-up should move up and down trying to focus.
It can be anything in sled drive circuity. I assume you have a service manual and have tested for voltages?

Yesterday I managed to play around with the CD. Voltages look reasonably fine (5/6% tolerance) except for PIN 15 on the IC101. It should read 0V instead it was around 2.4, same as PIN 14. That PIN is the one that should control the SLED motor. The R108 resistor has the correct value so I'm not sure what's causing the voltage to be wrong.
Another thing that happened was that, out of the blue, both the SPIN and SLED motor started spinning very fast (the gear was taken out so nothing happened to the pickup) so something odd is going on with the motor circuit.
It might be down to some bad capacitor but I counted at least 49 electrolytes caps, not sure if it is worth replacing them all.

 

[Ullar]

Yesterday I managed to play around with the CD. Voltages look reasonably fine (5/6% tolerance) except for PIN 15 on the IC101. It should read 0V instead it was around 2.4, same as PIN 14. That PIN is the one that should control the SLED motor. The R108 resistor has the correct value so I'm not sure what's causing the voltage to be wrong.
Another thing that happened was that, out of the blue, both the SPIN and SLED motor started spinning very fast (the gear was taken out so nothing happened to the pickup) so something odd is going on with the motor circuit.
It might be down to some bad capacitor but I counted at least 49 electrolytes caps, not sure if it is worth replacing them all.

Could be bad solder somewhere or bad contact in motor cable. Take a good look with magnifying glass and re-solder connectors and other suspicious looking details. Good luck!

 

[Ullar]

What are IC103 pins 8 and 14 doing?

IC103 pin 8 is 0.2 V rising occasionally up to 0.4 V for about half of second.
IC103 pin 14 is centered at 0 V, 0.04 to 0.1 Vpp.
Does that make sense?

Thank you dr*audio for your support. Your input is very valuable and greatly appreciated.

I was playing around with Tracking gain and -offset settings. When settings where like suggested in the manual sled traveled to the center of the disc and remained there. Reducing gain and turning offset pot counter clock wise I could get the sledge to slide outwards from the center. After trimming offset slightly clockwise from that setting sled started to move towards the center of the disc, step by step. And remained at the end in the center most position.

My question is if I can still hope for a relatively simple solution or it is most likely the problem with some IC-s malfunctioning?

 

[penmarker]

That's what dr*audio suggested: If the lens doesn't move after the pickup finds home, either the pickup is bad or the cable for the pickup is broken, or the drive IC is bad, or there is a power supply problem. Some players have IC protectors that look like transistors with only 2 leads. They go open.

Thank you very much. I checked around the diver IC for the protectors but don't see any.
Ruled out faulty drive IC because it has two; one for tray sled and one for laser assembly. swapped between the two and the tray works normally
Don't have an oscilloscope to check the power supply so recapped the whole boards including the front panel that controls the laser (it has a crystal beside an IC). No effect

Perhaps the pickup is bad?

What's worrying is sometimes it would attempt to focus. Probably 10% of the time I can see the lens move up and down and the laser lit up. 90% of the time it does not come alive at all. But when I put on a CD to try play it there's no signs of life from the laser or the spindle motor.

 

[dr*audio]

Thank you very much. I checked around the diver IC for the protectors but don't see any.
Ruled out faulty drive IC because it has two; one for tray sled and one for laser assembly. swapped between the two and the tray works normally
Don't have an oscilloscope to check the power supply so recapped the whole boards including the front panel that controls the laser (it has a crystal beside an IC). No effect

Perhaps the pickup is bad?

What's worrying is sometimes it would attempt to focus. Probably 10% of the time I can see the lens move up and down and the laser lit up. 90% of the time it does not come alive at all. But when I put on a CD to try play it there's no signs of life from the laser or the spindle motor.

You need a scope to troubleshoot this properly, otherwise you are operating blind.

 

[Ullar]

Thank you very much. I checked around the diver IC for the protectors but don't see any.
Ruled out faulty drive IC because it has two; one for tray sled and one for laser assembly. swapped between the two and the tray works normally
Don't have an oscilloscope to check the power supply so recapped the whole boards including the front panel that controls the laser (it has a crystal beside an IC). No effect

Perhaps the pickup is bad?

What's worrying is sometimes it would attempt to focus. Probably 10% of the time I can see the lens move up and down and the laser lit up. 90% of the time it does not come alive at all. But when I put on a CD to try play it there's no signs of life from the laser or the spindle motor.

So the problem is somewhat intermittent?
1) Is there a micro switch that should register the closure of the tray? Does it work properly?
2) If you initially move sled away from the center of the disc, does it move back to the center when you insert a disc?

 

[Ullar]

Hi everybody,
The saga of my SL-P1300 continues. I was checking voltages for ripple with the oscilloscope and decided to look on sled and sled drive voltages too. And that's what I found.
Sled voltage with no disc:

With disc in the player the voltage jumps around on positive and negative side but the oscillation remains.
Is that normal behavior?
Here is voltage on the input of sled drive transistors:

I think that it's somehow generated in sled drive feedback loop as it's absent anywhere else.
What do you think? Please help me out here.

 

[urbom]

Okay, so I have an Onkyo dx-1400 and I did a com;lete recap. but I got caps 911 and 912, main power smoothing caps backwards. Plugged it in through a dbt and both caps blew out. I have replaced them with new caps, but the unit does not work. tray moves in and out, only see the lazer move up and down (focus), disk does not spin. where do I look for damage?

 

[dr*audio]

Hi everybody,
The saga of my SL-P1300 continues. I was checking voltages for ripple with the oscilloscope and decided to look on sled and sled drive voltages too. And that's what I found.
Sled voltage with no disc:
View attachment 3360034
With disc in the player the voltage jumps around on positive and negative side but the oscillation remains.
Is that normal behavior?
Here is voltage on the input of sled drive transistors:
View attachment 3360040
I think that it's somehow generated in sled drive feedback loop as it's absent anywhere else.
What do you think? Please help me out here.

The drive ic is oscillating. Try adding a 100 ohm resistor in series with the output.

 

[dr*audio]

Okay, so I have an Onkyo dx-1400 and I did a com;lete recap. but I got caps 911 and 912, main power smoothing caps backwards. Plugged it in through a dbt and both caps blew out. I have replaced them with new caps, but the unit does not work. tray moves in and out, only see the lazer move up and down (focus), disk does not spin. where do I look for damage?

If it worked before the recap, check all the power supply voltages. If it didn't work before the recap, the laser is bad.

 

[Ullar]

The drive ic is oscillating. Try adding a 100 ohm resistor in series with the output.

Thank you dr*audio. Added the resistor. Still the same oscillations. Changed also sled servo IC (IC103). Still no charm.
Should I start to check the remaining components in sled drive one by one?

 

[urbom]

Thank you dr*audio. It did indeed work before the recap. I assume I check the voltages on the points where they get to the board or do I check someplace else?

 

[dr*audio]

Thank you dr*audio. It did indeed work before the recap. I assume I check the voltages on the points where they get to the board or do I check someplace else?

You can start with the power supply section of the schematic and check the voltages there. Usually there is a 5V supply for the laser, you could check that also.

 

[dr*audio]

Thank you dr*audio. Added the resistor. Still the same oscillations. Changed also sled servo IC (IC103). Still no charm.
Should I start to check the remaining components in sled drive one by one?

I'll have to look at the schematic. It has to be either the IC or maybe there is a cap in the feedback loop that is bad.

 

[MaVeDo]

Hi.

I bought a Marantz CD6007 4 months ago.

I'll tell you, I started having reading errors in the first month, once a week, but I let them go. They seemed like minor things to me.

Now they happen (2 weeks ago) continuously every time I put a disc in the next day after using it. It doesn't matter if I wait 15 or 30 minutes letting it warm up. The temperatures here are between 7 and 22 degrees so I rule out condensation.

This, according to my observation, happens after turning it on only with the first CD in its first tracks 1-2-3: skips, silences, sounds like "tch", etc.

Then I open the tray, put the CD in again until it plays the whole thing. Anyway, it's a bit annoying to wait for it to play properly.

The playback after the first CD is without problems. So I can listen to 2 or 3 more CDs and no playback errors occur.

I even tried scratched or marked CDs and it plays them fine; the problem is the first one. Occasionally it skipped on discs after the first one, but it was an issue twice according to what I noted and could be due to various causes.

The strange thing is that it is only on the first disc, on the first tracks, as if when you turn it on it lacks power to play or something like that.

Any ideas?

Greetings

 

[dr*audio]

Hi.

I bought a Marantz CD6007 4 months ago.

I'll tell you, I started having reading errors in the first month, once a week, but I let them go. They seemed like minor things to me.

Now they happen (2 weeks ago) continuously every time I put a disc in the next day after using it. It doesn't matter if I wait 15 or 30 minutes letting it warm up. The temperatures here are between 7 and 22 degrees so I rule out condensation.

This, according to my observation, happens after turning it on only with the first CD in its first tracks 1-2-3: skips, silences, sounds like "tch", etc.

Then I open the tray, put the CD in again until it plays the whole thing. Anyway, it's a bit annoying to wait for it to play properly.

The playback after the first CD is without problems. So I can listen to 2 or 3 more CDs and no playback errors occur.

I even tried scratched or marked CDs and it plays them fine; the problem is the first one. Occasionally it skipped on discs after the first one, but it was an issue twice according to what I noted and could be due to various causes.

The strange thing is that it is only on the first disc, on the first tracks, as if when you turn it on it lacks power to play or something like that.

Any ideas?

Greetings

You'd need an oscilloscope with minimum 60MHz bandwidth to troubleshoot this. If you don't have one you'll have to find a qualified tech.