Troubleshooting CD Players
- Thread starter dr*audio
- Start date
without dismounting the pickup (very Electro Static Discharges sensitive) for cleaning the bearings it can stay hardened grease inside.
Vertical position to use gravity you need to soak with IPA the swab and pass all arround the pikup assembly bearing (red cercle)
to flush away the grease...
don't use IPA to clean len as it tends to blur it, instead use cotton swab with one drop of glasses cleaner (and the other dry side cotton swab to finish cleaning)
both sides
Vertical position to use gravity you need to soak with IPA the swab and pass all arround the pikup assembly bearing (red cercle)
to flush away the grease...
don't use IPA to clean len as it tends to blur it, instead use cotton swab with one drop of glasses cleaner (and the other dry side cotton swab to finish cleaning)
both sides
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dr*audio
Fish fingers and custard!
It's not the pickup, it's the sled motor. You can verify this by monitoring the voltage on the sled motor with a meter while playing a CD. The voltage should steadily climb to 100mV - 500mV then drop back to 0V or a bit negative as the sled motor moves to correct the error. If it goes above 1V and then goes negative the motor has a bad spot and doesn't move until the voltage is 1V or more, then it jumps too far and the correction voltage goes negative.
It may not be possible to find a replacement motor but a complete mechanical assembly with the pickup and motors may be available. Looks like a Philips mechanism. Look in the service manual to see if there is a part number for the sled motor. If not, look on the mechanism for a part number. If it's a Philips it will say VAM and some numbers. Liberty Electronics on E-bay may have it.
I traced the wires from the spindle motor and the sled motor to where they connected on the circuit boards and measured the voltage at the connectors. I didn't solder wires on but used a couple of needles stuck in by the wires on the back of the connector, as shown in the photo, one one the black wire, and one on the red wire. I did this for the spindle motor and the sled motor.
The spindle motor measured a steady 5.1-V while running.
The sled motor voltage would run in the range dr*audio mentioned, 100 to 500mV, then increase up to about 1100 or 1200mV, drop down to 0 or a bit below, dance around, then stabilize at less than 500mV for awhile, then repeat. On the CD I've been running this whole time, there was frequently a skip on track 6 at 24-seconds. While doing the voltage measurement, it was interesting the voltage would peak out at about 1100mV at that same spot, and then drop down, as described. The CD did not skip, however. (I have videos of the Fluke meter next to the CD display showing the voltage and CD Track/time display, but it doesn't look like videos can be attached.)
Next move was to tilt the player up and add some Triflow lubricant to the metal rod, as recommended by phil916. I tilted the unit both ways. Then ran the sled through the full range of motion from track-1 to track-21 and back, several times, just to wipe the lube around. The Voltage peak on Track 6 shifted to the 18-second point, and at 24-seconds the voltage was back down again. Don't know if that is important, or not.
Both the spindle and sled motors are Mabuchi RF300C-11440 models. There are some used ones on eBay, but Liberty Electronics didn't have any listed.
Anyway, the CD player didn't skip today, through three cycles of one CD, and one playing of another CD. I guess that's the desired outcome - perhaps cleaning and lubing the rod was of some benefit? (The first play-through was before lubing, today.)
Thanks for everyone's help.
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dr*audio
Fish fingers and custard!
I'm sure the lubing helped, but I think you need a new sled motor. You can try injecting Deoxit into any openings in the end of the motor where the wires go, in hopes of getting it to the commutator, then skipping through the tracks on the CD back and forth a few times, or connecting a battery to the motor to run it back and forth. But I would search for a new motor or the complete mechanism, because sooner or later, that motor is going to give out. These little ones don't last long.
OK, got it. Thanks for sharing your wisdom on these things.
I got a Sony CDP-C305 for free - recycler said it wouldn't eject. Well, I got that working, kind of. The belts on the machine are old and worn (1990), but functional.
The symptom is that sometimes it doesn't spin the disc or try to read it. It lifts the disc into place but then stops. When this happens, the CD player gets confused, and the Open/Close button only spins the carousel. It will not eject. At that point, the disc number indicator is incorrect.
So power off, eject, then it's OK, it resets itself. This only happens sometimes. When it does spin the disc, it will play, and seems to play fine. I cleaned the lens with 91% IPA and a q-tip.
To me this sounds like an electronic problem, not mechanical. Anyone seen this?
The symptom is that sometimes it doesn't spin the disc or try to read it. It lifts the disc into place but then stops. When this happens, the CD player gets confused, and the Open/Close button only spins the carousel. It will not eject. At that point, the disc number indicator is incorrect.
So power off, eject, then it's OK, it resets itself. This only happens sometimes. When it does spin the disc, it will play, and seems to play fine. I cleaned the lens with 91% IPA and a q-tip.
To me this sounds like an electronic problem, not mechanical. Anyone seen this?
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dr*audio
Fish fingers and custard!
Replace the belts with the correct size. Sounds like it isn't loading correctly. You can also try cleaning the switch that tells it the tray is all the way in, and the one that tells it the mechanism is all the way up. Also, some schmuck may have lost the plastic transport locking key that goes in the bottom and then the player was set down too hard, and the mechanism popped out of the correct groove in the loading cam gear. There is a little pin on the mechanism that runs in a track on the cam. It should be in the track with grease in it, not the other track.
Thanks for the reply. The belts are going to be a challenge because one of them is a cogged belt that isn't made right now. As I understand there IS a new belt available for the 1991-1999 models, but this predates that. I guess I can check with the unit open to see if the cogged belt is running its mechanism correctly after the freakout begins.
The thing is, the player behaves normally for a while after startup, then suddenly loses its mind. That makes me think it's a logic board problem.
The switches may not be clean enough. In my previous restoration, the limit switch loses contact at the furthest end of the travel. And my home switch has high resistance even though it beeped on continuity meter. So it could load up properly but randomly dies during spin-up / TOC loading.
Could be worth a look, cheaper and easier than looking at the logic.
Could be worth a look, cheaper and easier than looking at the logic.
Thanks, I'll look into that. I'm not sure what the limit or home switches are, but will check the service manual.
The limit switches tell the controller whether the tray is fully open or closed; some systems have a 2-way switch, others usually have 2 simple switches. Typically located at the ends of the transport (the tray will trigger them at the fully out / closed position).
Home switch is between the spindle and sled motor, the laser will trigger it (innermost position of the CD).
Home switch is between the spindle and sled motor, the laser will trigger it (innermost position of the CD).
Ok, I going to post this as a request for some help with my recently purchased Philips CD880. I purchased the unit as a repair or parts unit as I know they have some sought after parts within. Well after popping the cover I have discovered the player is not completely dead as I can make it play with some prodding. Below is the sequence of what happens:
1. Power on the player, all display lights come on except the light for the power switch itself (burnt out bulb)
2. Push the open drawer button, drawer opens as normal.
3. Push play, push open drawer button, or gently push on drawer. Drawer closes as normal.
4. Display shows ”Disc” but the disc does not move. Then after a few moments it displays “Disc Error”
5. I gently spin the disc counterclockwise and press play. The disc spins for a few seconds and displays TOC etc.
6. Press play again and the CD begins playing and plays fine through the entire disc with no futher issues.
From what I can see there are at least two belts which I intend to replace as I would say they have never been replaced. Not sure if belt replacement will solve my problem. I have read that there is a potentially weak 33uf capacitor on the control board on these players, but not sure if that might cause the load/read error or not. Any recommendations are appreciated. I know the Philips players are not really recommended as the lasers are no longer available, but I have a CD650 that still works like the day I bought it new so I have a bit of a soft spot for vintage Philips. I think this CD880 is worth salvaging and repairing as the Dutch Audio Classics website indicates.
Thanks Don
1. Power on the player, all display lights come on except the light for the power switch itself (burnt out bulb)
2. Push the open drawer button, drawer opens as normal.
3. Push play, push open drawer button, or gently push on drawer. Drawer closes as normal.
4. Display shows ”Disc” but the disc does not move. Then after a few moments it displays “Disc Error”
5. I gently spin the disc counterclockwise and press play. The disc spins for a few seconds and displays TOC etc.
6. Press play again and the CD begins playing and plays fine through the entire disc with no futher issues.
From what I can see there are at least two belts which I intend to replace as I would say they have never been replaced. Not sure if belt replacement will solve my problem. I have read that there is a potentially weak 33uf capacitor on the control board on these players, but not sure if that might cause the load/read error or not. Any recommendations are appreciated. I know the Philips players are not really recommended as the lasers are no longer available, but I have a CD650 that still works like the day I bought it new so I have a bit of a soft spot for vintage Philips. I think this CD880 is worth salvaging and repairing as the Dutch Audio Classics website indicates.
Thanks Don
You can try changing the belts / caps etc, but maybe you can lube the spindle motor first. Sounds like it needs some encouragement to run.
I will change the belts because after 30 years or more I am sure they are worn. I will also lube the spindle motor as well as that is also a maintenance action that should be done.
As far as recapping I know the capacitors are old but I might hold off on that as it requires a fair amount of disassembly and knowledge which I am not experienced with so I might bring it to a tech to handle that work, although the current sound quality of the player is excellent when it’s playing.
dr*audio
Fish fingers and custard!
Needs a new disc motor. You can try injecting Deoxit into the holes in the bottom of the motor and it will probably work for a few months.
Hello dr*audio,
I gather the disc motor is the small motor that is mounted on the side of the transport mechanism that is connected by the small thin belt? If that is correct, I will try some deoxit into the motor as you have indicated then I will try to source a new one at the same time as when I purchase the replacement belts.
Thanks very much for your recommendation.
Don
Hi dr*audio,
Upon further investigation, I am understanding that the disc motor is actually the same as the spindle motor or turntable motor which is located at the bottom of the cd transport mechanism that spins the actual disc.
I see that it will require to remove the cd transport mechanism from the cd player in order to get to the motor which is mounted on the bottom of the mechanism. I might decide to give it a try or I might just bring it in to a technician to have the motor replaced as pulling apart the cd player more than once is not likely worth the effort.
Thanks again,
Don
I did some more investigation and have found that the disc motor on my CD880 is not a regular Mabuchi or Matsushita disc motor but instead it is a brushless turntable motor as shown in the attached diagram.
With that in mind, I think I will get the motor checked and cleaned and have the 33uf capacitor changed on the daughter control board and see what the outcome is before I try to obtain the hard to source turntable motor.
With that in mind, I think I will get the motor checked and cleaned and have the 33uf capacitor changed on the daughter control board and see what the outcome is before I try to obtain the hard to source turntable motor.