Good evening, I just received a nice Marantz CD-273 which is supposed to go to my daughter who just discovered how good CDs are. The seller put it into the box upside down (argh) directly on the floor (noooo) with all packing material on its belly. When it came, the transport was unstuck (see photo). I realised this only when it would not open.
I adjusted the mechanism and it opens and closes again. But the player still does not play. First oddity: as long as the tray is open the tray motor spins. Main problem: the player does not play CDs. When I insert one and press "close" the tray goes in, the laser does it focus work, but then stops and the display shows all zeros. and this is it. most keys, if touched, give an "error" message. to me, this seems like an electrical, rather mechanical problem. but maybe something got unstuck and I did not see it? the laser unit turns freely on its swing-arm, however.
It's entirely possible that the unit was already defective when the seller sent it. I have some experience with philips-based systems which need to have the griplets reflowed and caps in the servo circuits changed, but before getting all over the player in shotgun-fashion some of you might know the symptoms and can direct me towards a specific solution.
state upon arrival... now mechanically fixed, but player still defective.
I adjusted the mechanism and it opens and closes again. But the player still does not play. First oddity: as long as the tray is open the tray motor spins. Main problem: the player does not play CDs. When I insert one and press "close" the tray goes in, the laser does it focus work, but then stops and the display shows all zeros. and this is it. most keys, if touched, give an "error" message. to me, this seems like an electrical, rather mechanical problem. but maybe something got unstuck and I did not see it? the laser unit turns freely on its swing-arm, however.
It's entirely possible that the unit was already defective when the seller sent it. I have some experience with philips-based systems which need to have the griplets reflowed and caps in the servo circuits changed, but before getting all over the player in shotgun-fashion some of you might know the symptoms and can direct me towards a specific solution.
state upon arrival... now mechanically fixed, but player still defective.
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thinking aloud... maybe I did Not adjust the mechanic exactly as it is supposed to be and the contacts are not closed when the tray is out (motor running) and some others are open when the tray is in? I'll dive in it again... thank good the good old philips plastic players are so easy to dissemble 🙂 ideas?
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just checked: both switches work mechanically and are switched by the tray running out and in.
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If the tray motor does not spot spinning when the tray is out, the CPU isn't getting the 'open limit' signal, so either the switch isn't operating correctly or the signal isn't getting back. Are all the connectors fully plugged in? Also If the laser mech can't travel all of the way back to the centre it will not be able to read the TOC, which might be caused by something mechanical out of alignment. If the height of the platter has moved on the spindle the laser may not be able to focus on the disc. If the spindle shaft has bent the laser may not be able to follow the eccentricity of the track. A tiny drop of oil on the top bearing of the spindle motor can also alleviate shaft chatter which can cause reading issues on aged players.
Thanks! These are already a lot of tracks to follow. I triple-checked the connectors but will check them again on both ends. the laser mech is free to travel to both end points. The switches are operating in the sense that I see the contacts touch one another.
Update: I checked supply voltages. All seem normal apart from the -2 rail (-12v) which measures -10v. I did not check transistor 6314 as it is a SMD package on the solder side.
I replaced the caps on the servo board as those are known to cause strange behaviour. I also checked the transistor there, ok. Nothing of this helped so far.
The player does actually not spin the disk at all. No motor movement audible.
Looking at the servo board schematics I see that the -2 rail feeds op-amps (6103, 6104) relevant for focus drive, radial motor and motor control. so -10v instead ov -12v might be too low?
Marantz CD-273 power supply
Marantz CD-273 servo board, focus drive and turntable motor control with -2 rail
I replaced the caps on the servo board as those are known to cause strange behaviour. I also checked the transistor there, ok. Nothing of this helped so far.
The player does actually not spin the disk at all. No motor movement audible.
Looking at the servo board schematics I see that the -2 rail feeds op-amps (6103, 6104) relevant for focus drive, radial motor and motor control. so -10v instead ov -12v might be too low?
Marantz CD-273 power supply
Marantz CD-273 servo board, focus drive and turntable motor control with -2 rail
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will do that, thanks. I'll also check the two op-amps I in the motor circuits.
EDIT: turns out that I forget to connect a cable socket inside the transport. so the disc spins. still no reading, though, and all keys on the panel give an error message.
EDIT: turns out that I forget to connect a cable socket inside the transport. so the disc spins. still no reading, though, and all keys on the panel give an error message.
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I'm not sure why the -2 rail is labelled -12v. The other (+) side of the same bridge is labelled +10.5v, so I would have thought the (-) would be -10.5v less ~0.6v drop through Q6314, so I would have thought -2 rail would be ~ -10v.
Did you replace "the infamous blue C2103 33uF Philips cap" https://www.diyaudio.com/community/...ration-and-modding-of-a-marantz-cd273.350736/
Did you replace "the infamous blue C2103 33uF Philips cap" https://www.diyaudio.com/community/...ration-and-modding-of-a-marantz-cd273.350736/
Thanks for replying. As I wrote above, I replaced all electrolytics on the servo board, the blue 33uF axial first.
I think the resistor 3803 in the rectifier bridge explains the different voltages in the + and - rails. I was baffled about this, too.
I am not sure how to check if the laser beam is present at all. A bit afraid of hurting my eyes while searching for it. I also don't know if the radial drive works. so far the unit seems not to recognise a CD when I insert one, it seems to behave as though there was none. Does not even read the TOC.
With my limited experience in CD players I'd say the laser does not see the CD or there is no laser beam. I think the transport is ok now, so the disc is not on a wrong level. At least it does not seem so.
So there might be a fault with the laser unit (shock during shipment – upside down on box floor!) or a problem with one of the ICs controlling the laser or the radial motor. the procedure how to test the individual processors is well explained in the service manual but admittedly would be a steep learning curve for me.
The unit does not even go into self-diagnosis mode (to go there press lap/remain and both track change keys simultaneously on start-up). That might point to a flaw deeper down in the logic of the player.
For now I'll put the machine in my spare stash. It's a pity as it is a nice clean unit, easy to work on (recap main board) and it has the TDA1541A (the last 273 I had in my hands had the 1541). My daughter would have loved a midi-sized cd player :-(
I think the resistor 3803 in the rectifier bridge explains the different voltages in the + and - rails. I was baffled about this, too.
I am not sure how to check if the laser beam is present at all. A bit afraid of hurting my eyes while searching for it. I also don't know if the radial drive works. so far the unit seems not to recognise a CD when I insert one, it seems to behave as though there was none. Does not even read the TOC.
With my limited experience in CD players I'd say the laser does not see the CD or there is no laser beam. I think the transport is ok now, so the disc is not on a wrong level. At least it does not seem so.
So there might be a fault with the laser unit (shock during shipment – upside down on box floor!) or a problem with one of the ICs controlling the laser or the radial motor. the procedure how to test the individual processors is well explained in the service manual but admittedly would be a steep learning curve for me.
The unit does not even go into self-diagnosis mode (to go there press lap/remain and both track change keys simultaneously on start-up). That might point to a flaw deeper down in the logic of the player.
For now I'll put the machine in my spare stash. It's a pity as it is a nice clean unit, easy to work on (recap main board) and it has the TDA1541A (the last 273 I had in my hands had the 1541). My daughter would have loved a midi-sized cd player :-(
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Actually I did not put the CD-player in the stash but opened it up again. After having read some threads about the bad blue axials on Philip boards and the problematic griplets (contacts through the board) I resolved to recap the PCB and to reflow the griplets. Did the recap (all but main and op-amp power supplies) but did not thoroughly work through the griplets so far.
At this stage nothing new; still does not read the TOC. Would have been too nice just for New Year's eve.
While loading a CD, I looked under the CDM4/25 from the side and did not see the radial motor move. I also did not see any glow of the laser beam in reflection. So the radial motor really does not move; I'll track down why next. That might not be all of what's wrong but it is a trace to follow. I will also resolder all the griplets (by removing the old solder and resoldering them).
The laser might not work, that's another track. Does the radial motor move if there is no laser beam?
Will report, may take some time. Now that I recapped the mainboard this player needs to get rolling again. Thinking about getting a donor for the whole CDM4/25.
Have a good passage into 2021, you guys.
At this stage nothing new; still does not read the TOC. Would have been too nice just for New Year's eve.
While loading a CD, I looked under the CDM4/25 from the side and did not see the radial motor move. I also did not see any glow of the laser beam in reflection. So the radial motor really does not move; I'll track down why next. That might not be all of what's wrong but it is a trace to follow. I will also resolder all the griplets (by removing the old solder and resoldering them).
The laser might not work, that's another track. Does the radial motor move if there is no laser beam?
Will report, may take some time. Now that I recapped the mainboard this player needs to get rolling again. Thinking about getting a donor for the whole CDM4/25.
Have a good passage into 2021, you guys.
I believe that the laser, if working, will show up on a mobile phone camera, like the IR from a remote control does. I don't have one of these mechs to look at, however I would expect to see at least a bit of twitching as the reader attempts to find the TOC.
Thanks. I do not see any laser beam, and I can confirm that the swing arm does not move at all. Rail supply lines into the servo board beneath the transport are ok. I realized that the player does not have a CDM-2 fitted as in the service manual, but a CDM 4-25 (sticker on the transport). Unable to find any documentation for this variant.
The servo PCB is different from the one shown in the CDM-2. The servo board in my player has only one op-amp – rails look ok, although +-10v instead of 12, but that should not matter that much. The various board iterations beneath in the CDM-2 have at least two op-amps. Unfortunately I don't see a way to proceed with troubleshooting without a schematics of the actual servo board installed.
Looking for spares at the usual selling sites, I found one or two more similar players (Marantz CD-56 e.g.) of this vintage with the symptom of "switches on but does not read CD". So maybe this is something typical for certain components – ICs on the servo board? – breaking – which ones I am not longer optimistic to find out.
The culprit was not the blue axial Philips 33uF cap. I admit I did not resolder all the griplets, but my symptoms to me seem somehow to global to be attributed to them. When I'll feel like wasting some more hours I'll do the griplets.
It could be anything stopping the CD reader... but in my experience it's usually the simple things. 1st: nothing is going to work without the power supply, so check all of the rails. Volt accuracy is not nearly as important as whether there is a rail! 2nd: the things that blow are usually the circuits that drive things, e.g. the amps that drive the coils that move things. Often in a CD player the drivers are audio chips or audio-like circuits, so check for blown chip amps or output transistors. It is less likely (though entirely possible) that a processor chip has failed, but if a processor isn't working like it should it's often because of a supply voltage missing or sagging due to another fault, or an input to the processor not functioning correctly.
Ok, true. I will need to check all the rail voltages, those coming into the servo board, and those going out to the motors/the laser. I only checked the rails on the 5-pole-connector coming from the main board (ok) and the voltages arriving at the lone op-amp (ok).
I agree that the fault should be caused by something macroscopic like a blown transistor / diode or a broken trace or solder joint, not necessarily a fried chip.
The one transistor on my (undocumented, alas) CDM-4/25 servo board checked ok some days ago when I changed the blue cap (and all other electrolytics) on that PCB.
And I'll need to re-do the griplets.
I agree that the fault should be caused by something macroscopic like a blown transistor / diode or a broken trace or solder joint, not necessarily a fried chip.
The one transistor on my (undocumented, alas) CDM-4/25 servo board checked ok some days ago when I changed the blue cap (and all other electrolytics) on that PCB.
And I'll need to re-do the griplets.
TCA0372DP2 Motorola
ok maybe some progress.
checked the laser with window shades down, no laser beam at startup. then I checked voltages.
as I wrote above the cdm-4/25 servo board (screwed beneath the drive) is not documented. in the cd-273 service manual there are schematics and circuit-board layouts for different cdm-2 versions, but both do not map to the cdm-4/25 servo board.
the chips on "my" board are the TDA5708 photo diode signal processor (28 pins), the TDA5709 radial error processor (20 pins), a normal 8-pin dual opamp for the disc motor voltage regulation and a strange 16-pin dual opamp (Motorola TCA0372DP2). The Servo uP processor is on the main board.
the CDM-2 manual shows one version without the servo uP processor, but with 3 standard dual opamps. different, but maybe close.
anyway, I looked at the rail voltages. both +- incoming 10v and 5v rails are present at the connector on the servo board. the rails to the disk drive are also ok (disk spins when it is inserted).
then tested chip voltages. TDA5708 looks inconspicious; TDA5709 not done yet, Motorola 16-pin opamp has 8v at output B. output B feeds the + voltage to the radial motor, 8v permanently seems wrong. the radial motor does not turn when the drawer is closed.
all other inputs on the 16-pin opamp are good, +- voltages are ok. could it be faulty?
I'll check the voltages on the TDA7509 next and report.
Below the pinout of TCA0372DP2. strange chip.
ok maybe some progress.
checked the laser with window shades down, no laser beam at startup. then I checked voltages.
as I wrote above the cdm-4/25 servo board (screwed beneath the drive) is not documented. in the cd-273 service manual there are schematics and circuit-board layouts for different cdm-2 versions, but both do not map to the cdm-4/25 servo board.
the chips on "my" board are the TDA5708 photo diode signal processor (28 pins), the TDA5709 radial error processor (20 pins), a normal 8-pin dual opamp for the disc motor voltage regulation and a strange 16-pin dual opamp (Motorola TCA0372DP2). The Servo uP processor is on the main board.
the CDM-2 manual shows one version without the servo uP processor, but with 3 standard dual opamps. different, but maybe close.
anyway, I looked at the rail voltages. both +- incoming 10v and 5v rails are present at the connector on the servo board. the rails to the disk drive are also ok (disk spins when it is inserted).
then tested chip voltages. TDA5708 looks inconspicious; TDA5709 not done yet, Motorola 16-pin opamp has 8v at output B. output B feeds the + voltage to the radial motor, 8v permanently seems wrong. the radial motor does not turn when the drawer is closed.
all other inputs on the 16-pin opamp are good, +- voltages are ok. could it be faulty?
I'll check the voltages on the TDA7509 next and report.
Below the pinout of TCA0372DP2. strange chip.
You might get some clues from the TCA0372 data sheet: https://www.onsemi.com/pdf/datasheet/tca0372-d.pdf