Dear friends.
The CD player came with a rotted tray gear. After replacement I found the disc does not spin at all. When loading a CD or without CD, the motor very slightly nudged.
No service manuals but found out its nearly identical to the CEC CD2100 and has found the service manual for that.
But the document has no voltage markings so I am working blind. What voltage is sensible to test the disc motor so I can rule out the motor is faulty?
Is there a common issue causing the motor to not spin?
Picture is of a similar model (but not mine).
The CD player came with a rotted tray gear. After replacement I found the disc does not spin at all. When loading a CD or without CD, the motor very slightly nudged.
No service manuals but found out its nearly identical to the CEC CD2100 and has found the service manual for that.
But the document has no voltage markings so I am working blind. What voltage is sensible to test the disc motor so I can rule out the motor is faulty?
Is there a common issue causing the motor to not spin?
Picture is of a similar model (but not mine).
Attachments
I've traced back the lines from the disc motor to the IC104 marked in green. Pin 1,2 are the ones responsible for spinning the motor so I checked the pinouts for the +ve and -ve voltages. Power is supplied by C147,148 marked in red. Checked my parts bin and found suitable replacements so i replaced them. Voltages are +15V and -15V.
The motor now sputters intermittently. It looks like its ticking trying to spin stronger than previously but it still does not spin. If I leave it alone for long, sometimes it would spin half rotation or so and then stops.
Measuring the disc motor shows very little voltage going out.
I also probed the voltage rails when the tray motor spins and it sags quite a bit from 15V to around 13V when the tray moves in or out.
For those interested, IC104 responsible for disc motor is an LA6510. Anyone has some idea what else to probe?
The motor now sputters intermittently. It looks like its ticking trying to spin stronger than previously but it still does not spin. If I leave it alone for long, sometimes it would spin half rotation or so and then stops.
Measuring the disc motor shows very little voltage going out.
I also probed the voltage rails when the tray motor spins and it sags quite a bit from 15V to around 13V when the tray moves in or out.
For those interested, IC104 responsible for disc motor is an LA6510. Anyone has some idea what else to probe?
Attachments
Seems that I'm getting somewhere. Based on the functional block diagram, IC102 is responsible for sending the signal to spin disc motor via SPINDLE SERVO CONTROL.
I replaced the electrolytic capacitors around the IC and the disc motor now jitters quite strongly. Jitter is constant, erratic, and has no pattern to it. Power is fed by a voltage regulator but it outputs a stable 5V so I'm ruling that out.
Checking the IC102, YM7121C datasheet it shows pin 53 is disc motor +ve and pin 54 -ve.
Tracing the line with the thick green stroke, i've split the +ve and -ve towards the end. Blue is -ve.
Reading on +ve is a constant 0.9mv
Rreading on -ve is erratic, up to 20mv
Spindle Servo Control is fed by EFM Demodulation Sync Detection Clk Control. This is fed by IC101 which gets fed by the laser.
What I am thinking is, either IC102 is faulty and cannot provide a stable disc motor signal, or IC101 is faulty and cannot feed a stable signal to IC102.
I replaced the electrolytic capacitors around the IC and the disc motor now jitters quite strongly. Jitter is constant, erratic, and has no pattern to it. Power is fed by a voltage regulator but it outputs a stable 5V so I'm ruling that out.
Checking the IC102, YM7121C datasheet it shows pin 53 is disc motor +ve and pin 54 -ve.
Tracing the line with the thick green stroke, i've split the +ve and -ve towards the end. Blue is -ve.
Reading on +ve is a constant 0.9mv
Rreading on -ve is erratic, up to 20mv
Spindle Servo Control is fed by EFM Demodulation Sync Detection Clk Control. This is fed by IC101 which gets fed by the laser.
What I am thinking is, either IC102 is faulty and cannot provide a stable disc motor signal, or IC101 is faulty and cannot feed a stable signal to IC102.
Attachments
JUST A GENERAL NOTE:
After many years of servicing/maintaining & repairing Electro-Mechanical devices, I found that mechanical factors fail more than electric/electronic
factors.
With old CD players, the servo/mechanical feedback function actually 'drifts' before it fails. This leads to inability to read TOC and stops the motor spinning.
If you have a player without 'a myriad of servo adjustment pots' (like a combination lock to set in sequence) the true solution is to buy a new player.
Even if you have the situation to 'crack the combination lock', the player may remain out-of REDBOOK spec. meaning only certain discs play.
If I'm not mistaken, there have been many threads on this website regarding similar problems > usually un-solvable.
DON'T BE AFRAID TO UPGRADE > It's only money 🙂
After many years of servicing/maintaining & repairing Electro-Mechanical devices, I found that mechanical factors fail more than electric/electronic
factors.
With old CD players, the servo/mechanical feedback function actually 'drifts' before it fails. This leads to inability to read TOC and stops the motor spinning.
If you have a player without 'a myriad of servo adjustment pots' (like a combination lock to set in sequence) the true solution is to buy a new player.
Even if you have the situation to 'crack the combination lock', the player may remain out-of REDBOOK spec. meaning only certain discs play.
If I'm not mistaken, there have been many threads on this website regarding similar problems > usually un-solvable.
DON'T BE AFRAID TO UPGRADE > It's only money 🙂
That's true my friend. Upgrading is a lot more sensible most times.
However this unit seem to have a sentimental value to the owner and he requests it to be revived.
What's your opinion in this issue? The motor does not spin at all, with or without a disc. It only jitters and can be felt with my finger. The voltage is quite erratic on the negative motor signal from the IC.
The motor does jolt a little when turned on, probably from inrush.
This player does have a lot of adjustments, I counted six. But I have not touched them because I don't have an oscilloscope to make adjustments.
However this unit seem to have a sentimental value to the owner and he requests it to be revived.
What's your opinion in this issue? The motor does not spin at all, with or without a disc. It only jitters and can be felt with my finger. The voltage is quite erratic on the negative motor signal from the IC.
The motor does jolt a little when turned on, probably from inrush.
This player does have a lot of adjustments, I counted six. But I have not touched them because I don't have an oscilloscope to make adjustments.
AMAZING > you're dealing with a player that has 'the magical combination lock'.
I spent a whole day noting positions of pots & playing with the adjustments. I did get the player to 'play'.
Without an oscilloscope needed, you need to start playing with tracking gain & offset pots to see if you can get the disc to spin.
If you are successful with this, you are on your way to a long tedious 'trial & error' process to see if you can get discs playing.
If you succeed with this > it becomes a real 'memory/learning/intuitive' process to see how good you can get the player 🙂
PS.
Don't spray anything with solvent cleaner, but DO gently clean the laser lenz with a cotton bud & a touch of metho.
I spent a whole day noting positions of pots & playing with the adjustments. I did get the player to 'play'.
Without an oscilloscope needed, you need to start playing with tracking gain & offset pots to see if you can get the disc to spin.
If you are successful with this, you are on your way to a long tedious 'trial & error' process to see if you can get discs playing.
If you succeed with this > it becomes a real 'memory/learning/intuitive' process to see how good you can get the player 🙂
PS.
Don't spray anything with solvent cleaner, but DO gently clean the laser lenz with a cotton bud & a touch of metho.
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I lifted the leg of R157 that connects IC102 YM7121C to the motor driver IC and verified the disc motor -ve signal is jittering. So the motor is not receiving the correct signal to spin.
is it possible the YM7121C is faulty or is it just sending out what it is being fed with?
I'm looking at the block diagram and the datasheet for the ICs but not all labels are the same (probably use different terminology) so I'm not sure if the pinouts which pinouts are the signal ins for the YM7121C.
is it possible the YM7121C is faulty or is it just sending out what it is being fed with?
I'm looking at the block diagram and the datasheet for the ICs but not all labels are the same (probably use different terminology) so I'm not sure if the pinouts which pinouts are the signal ins for the YM7121C.
Attachments
My friends. I made a mistake while testing the CD player. I didn’t connect it to the DAC board assuming it wouldn’t matter (I just won’t have output). But it must’ve needed the grounding run through the whole system to work.
The motor no longer jitters and reading is stable.
however now we have another fault, which I don’t know simpler or more complex.
The lense does not move when tray loads, so the motor also doesn’t turn.
So we have now a laser that doesn’t read cd
The motor no longer jitters and reading is stable.
however now we have another fault, which I don’t know simpler or more complex.
The lense does not move when tray loads, so the motor also doesn’t turn.
So we have now a laser that doesn’t read cd
Yes ruled out bad motor. When the board wasn't completely connected it would jolt and jitter.
The laser also does not move up and down to focus at all. We can see it when we close the empty tray and looking at the lens. There's no movement.
The laser also does not move up and down to focus at all. We can see it when we close the empty tray and looking at the lens. There's no movement.
you need a service manual of a cd player, which was made as mass product, but with the same main PCB.
Parasound use same or at least very similar PCB - go to
https://insidehifi.blogspot.com/2020/11/parasound-cdc-1500.html
and under
so as
I have listed more models, which use also this basic PCB.
Unfortunately I haven't find service manual for this PCB with instructions in detail for a trouble shooting procedure.
The reason therefore is the fact, that this PCB was not in use in typical stand alone cd player devices and only in ghetto blaster boom box units according this description
http://lampizator.eu/LAMPIZATOR/REFERENCES/CEC/CEC TL-1X.html
Parasound use same or at least very similar PCB - go to
https://insidehifi.blogspot.com/2020/11/parasound-cdc-1500.html
and under
so as
I have listed more models, which use also this basic PCB.
Unfortunately I haven't find service manual for this PCB with instructions in detail for a trouble shooting procedure.
The reason therefore is the fact, that this PCB was not in use in typical stand alone cd player devices and only in ghetto blaster boom box units according this description
http://lampizator.eu/LAMPIZATOR/REFERENCES/CEC/CEC TL-1X.html
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What about the home switch? The switch that the laser would close, at the end of its travel to the middle of the tray.
I forgot to mention >
There is an adjustment pot that controls the initial 'kick-off spin' that allows the Table Of Contents to be read.
If TOC can't be read, nothing further will work regarding disc playing.
There is an adjustment pot that controls the initial 'kick-off spin' that allows the Table Of Contents to be read.
If TOC can't be read, nothing further will work regarding disc playing.
Thanks all for your suggestions.
After cleaning the home switch I turned it back on and I can see the laser turn on with my phone camera and the lens also moves up and down to focus. I put on a cd and tried again but nothing happened again.
I took out the CD and looked a the laser and it died again. Cycled the tray in and out but it does not move at all. I traced back the laser power supply and there's a 22uf electrolytic so I replaced it.
Turned it on and no signs of movement. Cycled the tray once and the laser started again (light and focusing movement). I placed a CD and tried playing again but nothing. Removed CD and looked at laser again and it doesn't light up or move at all.
I looked at the service manual I have (for a CEC CD2100, similar main board but different front panel board).
On the block diagram it shows the laser is controlled by IC301 LC6554H4440 (image attached) in the front panel which is common to players.
From a different forum they mentioned "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" so I pulled and reseated the connectors between main board and front panel board with the IC301.
Turn on and the laser lit up and moved again. But like previously, only once. I cycled the tray a few times so the laser touches the home switch but the laser stayed dead.
So this whole issue is intermittent. I don't think its the connection because if it runs, it should stay running unless something moved/expanded/contracted.
Is it the electrolytic capacitors? Do they work better after it is turned off for a while and they're discharged, then when turn on they are energised?
**Edit
I left it alone for a while and turned it back on. The laser moved to focus once. I popped in a CD but it died on me again.
I've cleaned the home switch and there's some intermittent behaviour. Bear with me, its a little long.
After cleaning the home switch I turned it back on and I can see the laser turn on with my phone camera and the lens also moves up and down to focus. I put on a cd and tried again but nothing happened again.
I took out the CD and looked a the laser and it died again. Cycled the tray in and out but it does not move at all. I traced back the laser power supply and there's a 22uf electrolytic so I replaced it.
Turned it on and no signs of movement. Cycled the tray once and the laser started again (light and focusing movement). I placed a CD and tried playing again but nothing. Removed CD and looked at laser again and it doesn't light up or move at all.
I looked at the service manual I have (for a CEC CD2100, similar main board but different front panel board).
On the block diagram it shows the laser is controlled by IC301 LC6554H4440 (image attached) in the front panel which is common to players.
From a different forum they mentioned "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" so I pulled and reseated the connectors between main board and front panel board with the IC301.
Turn on and the laser lit up and moved again. But like previously, only once. I cycled the tray a few times so the laser touches the home switch but the laser stayed dead.
So this whole issue is intermittent. I don't think its the connection because if it runs, it should stay running unless something moved/expanded/contracted.
Is it the electrolytic capacitors? Do they work better after it is turned off for a while and they're discharged, then when turn on they are energised?
**Edit
I left it alone for a while and turned it back on. The laser moved to focus once. I popped in a CD but it died on me again.
Attachments
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Without a scope I've been working blind. I cleaned the home switch and it reads less than 4ohm from several dozen/hundred ohms. Connections are solid. All electrolytics has been replaced with new. I've tried swapping the driver IC between sled motor and laser+spindle motor just in case the laser IC is burn, but both are working fine.
I've just ordered a laser module as a last ditch effort. Once it arrives I hope that fixes it.
I've just ordered a laser module as a last ditch effort. Once it arrives I hope that fixes it.
Hi all,
I'm happy to report the CD player now runs great.
The problem was spindle height too low, so the CD was too close to the laser.
Someone from a facebook repairs group suggested me to check it and sure enough it was 1mm too low. Margin of error is 0.10mm.
After carefully pressing it in using a clamp I got the height right and it fired up immediately.
I'm happy to report the CD player now runs great.
The problem was spindle height too low, so the CD was too close to the laser.
Someone from a facebook repairs group suggested me to check it and sure enough it was 1mm too low. Margin of error is 0.10mm.
After carefully pressing it in using a clamp I got the height right and it fired up immediately.
Unfortunately I celebrated too early.
The deck is still somewhat faulty. As if there’s some sort of protection that kicks in after a period of time.
When first start up it reads and plays fine, but after a while it stops reading.
Pressing next/prev or play/pause will reflect on the screen which should not happen because if there’s no CD or it cannot read, the screen should show 0:00 and doesn’t respond to buttons.
If I turn off the player for a long time (20 minutes maybe?) it will work again, but it will stop reading CDs again after a while
The deck is still somewhat faulty. As if there’s some sort of protection that kicks in after a period of time.
When first start up it reads and plays fine, but after a while it stops reading.
Pressing next/prev or play/pause will reflect on the screen which should not happen because if there’s no CD or it cannot read, the screen should show 0:00 and doesn’t respond to buttons.
If I turn off the player for a long time (20 minutes maybe?) it will work again, but it will stop reading CDs again after a while
check out post #30+40 under
maybe this effect provide your observed things.
maybe this effect provide your observed things.
Thank you very much. I’ve found out what was wrong with it. Sorry it slipped my mind I should’ve updated it here.
The unit came with an original belt. My go to servicing is to replace it but my black replacement belt is thicker and stiffer.
When the laser moves to home it’s supposed to back out and release the leaf switch to initiate focus. The new belt is too thick and stiff, so it rubbed against the laser sled.
After a few cycles the belt settles into the grooves loosely so it rubbed the laser more.
It couldn’t back away from the leaf switch to laser doesn’t start.
I replaced the belt to its original one and it runs well. There’s plenty clearance with the thinner belt so laser moves freely and can crawl away from the leaf switch.
The unit came with an original belt. My go to servicing is to replace it but my black replacement belt is thicker and stiffer.
When the laser moves to home it’s supposed to back out and release the leaf switch to initiate focus. The new belt is too thick and stiff, so it rubbed against the laser sled.
After a few cycles the belt settles into the grooves loosely so it rubbed the laser more.
It couldn’t back away from the leaf switch to laser doesn’t start.
I replaced the belt to its original one and it runs well. There’s plenty clearance with the thinner belt so laser moves freely and can crawl away from the leaf switch.