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Troubleshooting CD Players

cma2032 said:
I have a GE CD player from 1990 (model 11-8000A). The CD will start to spin, display reads "00" and then the CD will stop and the display clears. If I take the top off, I can see that the laser is trying to focus, but it will not move along the rails at all (except manually, by turning the gears). Is it reasonable to assume the DC motor for the slide mechanism is dead? It's a MABUCHI RF-310T-11400.

I have also tried lubricating the rails and cleaning the laser, which didn't solve the issue.
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This player was probably made by Goldstar, since they owned GE at this time.
You need an oscilloscope to see what is happening. Most players will not spin the disc unless they have achieved focus lock but some just start to spin immediately. I don't remember what Goldstar players did. You need to look at the rf signal with the scope and see if it is 1.5V p-p. The Mabuchi sled motors almost never go bad. If you move it to the middle of it's travel, then put a CD in and start it, does the laser move to the inside?
 
dr*audio said:
You need an oscilloscope to see what is happening. … You need to look at the rf signal with the scope and see if it is 1.5V p-p.
Click to expand...

Unfortunately I don't have access to an oscilloscope without buying one, and I'm not sure i can justify that. Would it be reasonable in your opinion to just replace the laser and see if that does it? It's a KSS-150A. It looks like ones at least purporting to be that model are readily available from Chinese vendors, but I don't know if they're newly manufactured.

dr*audio said:
The Mabuchi sled motors almost never go bad. If you move it to the middle of it's travel, then put a CD in and start it, does the laser move to the inside?
Click to expand...

It does not move, unforunately.
 
cma2032 said:
Unfortunately I don't have access to an oscilloscope without buying one, and I'm not sure i can justify that. Would it be reasonable in your opinion to just replace the laser and see if that does it? It's a KSS-150A. It looks like ones at least purporting to be that model are readily available from Chinese vendors, but I don't know if they're newly manufactured.



It does not move, unforunately.
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I suspect another problem. A bad laser would not cause the sled not to move. Connect a DMM across the sled motor and see if there is voltage there when you turn it on with the sled in the middle. If there is no voltage the motor is not the problem. Should be at least 1V across the motor when it's supposed to move. There could be a bad drive IC or power supply problem.
FYI, the replacement laser for the KSS-150A is a KSS-210A and Liberty Electronics on Ebay sells good ones. I wouldn't buy it from anyone else. But don't buy it until we figure out why the sled doesn't move.
 
dr*audio said:
I suspect another problem. A bad laser would not cause the sled not to move. Connect a DMM across the sled motor and see if there is voltage there when you turn it on with the sled in the middle. If there is no voltage the motor is not the problem. Should be at least 1V across the motor when it's supposed to move. There could be a bad drive IC or power supply problem.
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So I followed your instructions and measured across the sled motor, and I got 1.64V for a few seconds, then it dropped down to nothing (I presume when it stopped trying to move). I repeated the operation a few times to verify.
 
cma2032 said:
So I followed your instructions and measured across the sled motor, and I got 1.64V for a few seconds, then it dropped down to nothing (I presume when it stopped trying to move). I repeated the operation a few times to verify.
Click to expand...
Ok, bad sled motor, then. You may be able to revive it at least temporarily, to check out the rest of the player. Remove the motor. If you look near where the wires connect to the motor there should be a couple of small holes in the motor. Inject Deoxit into the holes and then connect a power supply or a 9V battery to the motor and run it for awhile. This will clean the commutator. When you get it to where a single AA battery will make it turn, reinstall the motor and try again.
 
dr*audio said:
Ok, bad sled motor, then. You may be able to revive it at least temporarily, to check out the rest of the player. Remove the motor. If you look near where the wires connect to the motor there should be a couple of small holes in the motor. Inject Deoxit into the holes and then connect a power supply or a 9V battery to the motor and run it for awhile. This will clean the commutator. When you get it to where a single AA battery will make it turn, reinstall the motor and try again.
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So I think we're in business now. I followed your instructions (I did have a minor hiccup when removing the sled motor—side note: do you know of any right-angle precision screwdrivers?), and it didn't immediately get the player working, but after I moved the lens to the middle and powered it on and off a few times, it was able to read the disc, and so far, it seems to be working. Thank you!!
 
I've got another for you @dr*audio

I have a Panasonic SL-PC364 from 1991. It's a 5-disc carousel player, and the carousel function works fine, the laser moves freely, and it will raise up and down to engage with the disc and start to spin. It gives up after about 10 seconds and lowers the disc, then moves onto the next one. I've tried to clean the lens and I disassembled to look for any obvious failures, but didn't see anything. At least visually (from an angle, obviously) it seem the laser might not be emitting any light at all—do you know if that is a common point of failure with this type of player? Is there a way to check if it's functioning without an oscilloscope?
 
cma2032 said:
I've got another for you @dr*audio

I have a Panasonic SL-PC364 from 1991. It's a 5-disc carousel player, and the carousel function works fine, the laser moves freely, and it will raise up and down to engage with the disc and start to spin. It gives up after about 10 seconds and lowers the disc, then moves onto the next one. I've tried to clean the lens and I disassembled to look for any obvious failures, but didn't see anything. At least visually (from an angle, obviously) it seem the laser might not be emitting any light at all—do you know if that is a common point of failure with this type of player? Is there a way to check if it's functioning without an oscilloscope?
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The light that the laser emits is invisible to the human eye, but even without a scope I can tell you that the laser power is low. It's good enough to achieve focus lock (because it spins) but it won't read the TOC because the laser is shot. There are no lasers available for this. Can it and look for something that uses a KSS-150A, KSS-210A, KSS-240A, or KSS213 laser.
 
dr*audio said:
The light that the laser emits is invisible to the human eye, but even without a scope I can tell you that the laser power is low. It's good enough to achieve focus lock (because it spins) but it won't read the TOC because the laser is shot. There are no lasers available for this. Can it and look for something that uses a KSS-150A, KSS-210A, KSS-240A, or KSS213 laser.
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Do you know what laser it uses? I couldn't see any part # on it without taking out that whole chunk from the board
 
I'm surprised that nobody has figured out how to rebuild these laser assemblies with new laser diodes. Probably crazy talk.
 
hello @dr*audio I have an issue with a Sony CDP-X555ES. I power the unit on and the pickup rises but it does not spin, the display shows a 0. The open and close button does not work. I power the unit off and if I try to power it on again the unit does not power on any more. If I unplug the power cord and wait a minute or less, then it powers on and the same behavior that I described happens. If I power the unit on when the drawer is open, the drawer closes and repeats the same behavior. If I hold the open drawer button when I power the unit on, the drawer opens, then I can push the button and it closes and repeats the same actions. I disassembled both leaf switches and cleaned them and this didn't help, I also replaced the belt, and nothing changed. I cleaned old lube and applied new on the drawer's gear track and also lubricated the sled rail, but nothing helps.
Do you have an idea what the issue may be?
 
calavera68 said:
hello @dr*audio I have an issue with a Sony CDP-X555ES. I power the unit on and the pickup rises but it does not spin, the display shows a 0. The open and close button does not work. I power the unit off and if I try to power it on again the unit does not power on any more. If I unplug the power cord and wait a minute or less, then it powers on and the same behavior that I described happens. If I power the unit on when the drawer is open, the drawer closes and repeats the same behavior. If I hold the open drawer button when I power the unit on, the drawer opens, then I can push the button and it closes and repeats the same actions. I disassembled both leaf switches and cleaned them and this didn't help, I also replaced the belt, and nothing changed. I cleaned old lube and applied new on the drawer's gear track and also lubricated the sled rail, but nothing helps.
Do you have an idea what the issue may be?
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Does the lens in the pickup move up and down?
 
It does not seem to move up and down. I tried to upload a video, but I can only upload pictures. From the celular camera I can see the laser does turn on.
 
calavera68 said:
It does not seem to move up and down. I tried to upload a video, but I can only upload pictures. From the celular camera I can see the laser does turn on.
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If the laser is on, the lens should be moving up and down for focus search.
If not, there are many possible causes and you need an oscilloscope to troubleshoot this.
1. Get the service manual.
2. Using the scope, look at the Focus Output going to the pickup and see if there is a signal going positive and negative. If not, look at the Focus signal from the Servo IC and see if it's there. If it is, the focus amp that drives the pickup could be bad or the power supply for the amp could have a problem.
3. If there is no Focus signal, the microprocessor is probably bad or not working. Check the 5V, ground, reset and clock.
 
Below are the readings I got on these points at the servo Board:

30v = 36.9v
+8v = 10.49v
-8v = -11.20v
FE1 = 0.075v
TE1 = 0.008v
FE0 = 0.174v
TE0 = 0.023v
FES = 0.026v
FD- = -0.028v
FD+ = 0.042v
TD- = -0.003v
TD+ = -0.006v
SD+ = 0.188v
SD- = 0v
+5v = 4.98v
-5v = -5.08v
WFCK = -0.004v
RST = 2.072v
 
calavera68 said:
Below are the readings I got on these points at the servo Board:

30v = 36.9v
+8v = 10.49v
-8v = -11.20v
FE1 = 0.075v
TE1 = 0.008v
FE0 = 0.174v
TE0 = 0.023v
FES = 0.026v
FD- = -0.028v
FD+ = 0.042v
TD- = -0.003v
TD+ = -0.006v
SD+ = 0.188v
SD- = 0v
+5v = 4.98v
-5v = -5.08v
WFCK = -0.004v
RST = 2.072v
Click to expand...

Almost all of these DC readings mean nothing. You need a scope to get meaningful readings.
However, "RST = 2.072v" tells the story here. Should be 5V. The micro will not run. Something is pulling it down. Check caps on the reset line.
 
dr*audio said:
However, "RST = 2.072v" tells the story here
Click to expand...
Yeah; bad cap on the simple RC reset line has been the downfall of many a device.

I don't like the 30V and +-8V readings, either, though I don't have the spec tolerances for them; they could be fine if they are loose tolerance (e.g. unregulated) rails. Thinking about it, if they are defined by transformer taps, they are both wrong by about the same ratio: ~25%. Is this unit configured correctly/rated for the local mains voltage?
 
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