Hello, although I do not participate much in the forum I am a regular reader.
I have purchased a Marantz cd73.
The player does not work, the drawer opens and closes, the "Laser" led is on and the green LEDs on the top cover light up. But it does nothing else.
You can hear the noise of the drawer motor running, but the arm does not work either.
The recommendations that I have read are about the power supply, I have measured and I have the voltages equal to the diagram.
Someone knows and can guide me where the problem may come from.
The image is borrowed from the web.
I have purchased a Marantz cd73.
The player does not work, the drawer opens and closes, the "Laser" led is on and the green LEDs on the top cover light up. But it does nothing else.
You can hear the noise of the drawer motor running, but the arm does not work either.
The recommendations that I have read are about the power supply, I have measured and I have the voltages equal to the diagram.
Someone knows and can guide me where the problem may come from.
The image is borrowed from the web.
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I've been repairing this model recently so I've come to quite some experience and knowledge about it. The exact problem you're experiencing is unknown to me, though. But I can indicate you a couple of things which are important: are you sure you're hearing the drawer motor, wouldn't that be the spindle motor? As you say that drawer opens and closes. Standby LED off is VERY strange, also laser light only goes on normally when you press PLAY. Player seems to be confused in its control logic, probably some signals wrong, inducing the Microcontroller to do wrong stuff. Have you checked that the micro switch in the left back end corner is correctly working? It's actuated by the drawer, detecting closed and open drawer. Panel not acting is normal, it doesn't show meaningful indication until disc TOC is read (and playing).
On the left PCB, there's a tiny switch, which allows changing between normal and service mode (in service mode, you can play a disc even with drawer open (not a good idea, though. But for servicing is important, as you can fix disc with magnet or other holder and with the mech underside free of the drawer, proceed with service/adjustment.). You could try this, though, as it goes around an eventually bad micro switch for drawer position (but try it with drawer IN, otherwise disc will fly! or hold it with magnet.).
Service manual for this player is hard to find, I only found shcematics, but you NEED the PCB layouts, so just get yourself the SM for Philips CD303, most important PCBs are the same (while others are different, but the base of the player is the same).
Finally, the green leds which illuminate player's interior are always ON, that's normal. Same for the logo lamp. Good luck. With some more testing, we might give some more indications or take some conclusions. Check signals starting from CD mech preamp PCB (tiny PCB underneath the mech, hard to get there - a tip: don't remove the drawer, instead, disassemble CD mech and take it carefully off the drawer which remains in open position. Then, you can make yourself a "support stand" and put the mech on it and connect all cables and have it working like this outside of player for servicing and measurements. Look at my thread for some photos. By all means, be careful with the flex cable!).
On the left PCB, there's a tiny switch, which allows changing between normal and service mode (in service mode, you can play a disc even with drawer open (not a good idea, though. But for servicing is important, as you can fix disc with magnet or other holder and with the mech underside free of the drawer, proceed with service/adjustment.). You could try this, though, as it goes around an eventually bad micro switch for drawer position (but try it with drawer IN, otherwise disc will fly! or hold it with magnet.).
Service manual for this player is hard to find, I only found shcematics, but you NEED the PCB layouts, so just get yourself the SM for Philips CD303, most important PCBs are the same (while others are different, but the base of the player is the same).
Finally, the green leds which illuminate player's interior are always ON, that's normal. Same for the logo lamp. Good luck. With some more testing, we might give some more indications or take some conclusions. Check signals starting from CD mech preamp PCB (tiny PCB underneath the mech, hard to get there - a tip: don't remove the drawer, instead, disassemble CD mech and take it carefully off the drawer which remains in open position. Then, you can make yourself a "support stand" and put the mech on it and connect all cables and have it working like this outside of player for servicing and measurements. Look at my thread for some photos. By all means, be careful with the flex cable!).
Thanks joydivision. I will look according to your indications and comment on the observations. His thread I have also observed.
After a few days of vacation we return to the subject.
Really the noise of continuous operation is the axis, the led "Laser" is always on. That's how it is.
The drive lever in the corner of the "P800" PCB I can't see from the outside, I should remove the PCB. Although the "click" is heard when moving the drawer.
Are there photographs or images about the disassembly of the "P800" ?. It does not seem very easy to remove.
Really the noise of continuous operation is the axis, the led "Laser" is always on. That's how it is.
The drive lever in the corner of the "P800" PCB I can't see from the outside, I should remove the PCB. Although the "click" is heard when moving the drawer.
Are there photographs or images about the disassembly of the "P800" ?. It does not seem very easy to remove.
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Have the service manual for this one. PM me your E-mail address and I will send it to you.
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Ok. So you're saying that the spindle motor (that spins the CD) is always running, as is the laser led always on? No matter if drawer in or out? Or only with drawer in? Does it make any change if you change position of the little switch on the left side PCB's top (it says "Normal" and "service", as I said, it's to be able to play a disc with drawer out, this means this puts the drawer position detection switch temporarily out of function). I don't think you should disassemble the drawer control PCB as this doesn't seem to be the problem.
I think this is a problem of logic control - you say the display doesn't react?
Are you sure that +5V is reallly getting to all boards? Especially the uPCs (MAB84.. something)
I think this is a problem of logic control - you say the display doesn't react?
Are you sure that +5V is reallly getting to all boards? Especially the uPCs (MAB84.. something)
Yes, that's right, the CD axis and the laser led are always working, with the drawer open and closed and even with the service switch on or off. Nothing else works, even the power led is off (although it gets 18v.)
You mean the MAB8420 on PCB "P 200" (servo) and PCB "P500" (Decoder)?
I will measure the 5v voltages in all the areas indicated.
You mean the MAB8420 on PCB "P 200" (servo) and PCB "P500" (Decoder)?
I will measure the 5v voltages in all the areas indicated.
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Yes, exactly that MAB8420, which are the two microprocessors in charge. But what you're saying is a really weird and highly abnormal situation: the power LED should definitely illuminate, especially if you measure a voltage at it. This sounds to me like a failure at level of Power supply board or even transformer (check if all secondaries are giving correct voltage and correctly connected to PSU board). Or maybe a missing ground to some of the PCBs. Check: if all PCBs correctly receive all necessary supply voltages and measure directly resistance of their ground planes/points to chassis ground to find any possible grounding problems. The CD73 I'm repairing had some problems with that (although not causing anything similar).
If Power supply works fine, there might be a problem with the connections (especially those "resistors" - small components in a row going through the metal cage, it's where the power supply lines go from PSU board to other boards, I think these are safety resistors of 0,1 ohm, but I'm not sure, they don't appear in the schematics I have, they are shown as direct connections. I only have incomplete schematics of CD73 and complete service manual of Philips CD303, which is a huge help, as they are really similar, but obviously there are differences).
Don't just measure the 5V, measure all supply lines.
The Power LED is driven by 12V coming from PSU board through cables connected to J852 of P800 drawer suppy, so this might be worth checking. Also check J851 where it is connected to P800. But the power LED not being ON might be a separate problem, don't take any quick conclusions.
The laser led is driven by Laser signal coming from uPC on servo board, which exits through connector C272 , wiring diagram says it's a yellow cable. You can also check directly at pin 25 of MAB8420 on servo board. It should be 0 at Play and 1 at STOP.
Seeing how the turntable motor is driven, I'd suggest checking if the related circuit has the correct supply voltages, as there are opamps involved which might stick their outputs to one supply rail if one of the symmetric supplies is missing, making the motor run permanently. This would be on servo board, check pins 4 and 8 of Q209 (MC1458), if -12 and +12 supply are present.
Check also if the control signal is right, which is MCES signal, controlled by SAA7020 for what I can see (pin 4). You can also check it at servo board, input pin 5 of MC1458, according to manual should be 0,1V at STOP and 2,7V at Play.
In the end I bet all this is a problem with power supply/grounds.
One last possibility that occured to me: the player has support for remote control, implemented around LM6416 on drawer PCB P800. This directly controls the "play, pause, next, etc" lines, so I can imagine that if this IC should die or have wrong power supply, maybe it could mess up the control lines, making the rest misbehave? But still this would not explain all of this, so I'm still convinced that it's a problem with PSU. Good luck and keep reporting 🙂
p.s: I've been thinking about what you said regariding power LED getting 18V, when I look at wiring diagram, I'm pretty sure it should get around 12V (unregulated, but 18V sounds way off!). Maybe this is the problem? Check the rectifiers on P.S.Board and eveyrthing.
If Power supply works fine, there might be a problem with the connections (especially those "resistors" - small components in a row going through the metal cage, it's where the power supply lines go from PSU board to other boards, I think these are safety resistors of 0,1 ohm, but I'm not sure, they don't appear in the schematics I have, they are shown as direct connections. I only have incomplete schematics of CD73 and complete service manual of Philips CD303, which is a huge help, as they are really similar, but obviously there are differences).
Don't just measure the 5V, measure all supply lines.
The Power LED is driven by 12V coming from PSU board through cables connected to J852 of P800 drawer suppy, so this might be worth checking. Also check J851 where it is connected to P800. But the power LED not being ON might be a separate problem, don't take any quick conclusions.
The laser led is driven by Laser signal coming from uPC on servo board, which exits through connector C272 , wiring diagram says it's a yellow cable. You can also check directly at pin 25 of MAB8420 on servo board. It should be 0 at Play and 1 at STOP.
Seeing how the turntable motor is driven, I'd suggest checking if the related circuit has the correct supply voltages, as there are opamps involved which might stick their outputs to one supply rail if one of the symmetric supplies is missing, making the motor run permanently. This would be on servo board, check pins 4 and 8 of Q209 (MC1458), if -12 and +12 supply are present.
Check also if the control signal is right, which is MCES signal, controlled by SAA7020 for what I can see (pin 4). You can also check it at servo board, input pin 5 of MC1458, according to manual should be 0,1V at STOP and 2,7V at Play.
In the end I bet all this is a problem with power supply/grounds.
One last possibility that occured to me: the player has support for remote control, implemented around LM6416 on drawer PCB P800. This directly controls the "play, pause, next, etc" lines, so I can imagine that if this IC should die or have wrong power supply, maybe it could mess up the control lines, making the rest misbehave? But still this would not explain all of this, so I'm still convinced that it's a problem with PSU. Good luck and keep reporting 🙂
p.s: I've been thinking about what you said regariding power LED getting 18V, when I look at wiring diagram, I'm pretty sure it should get around 12V (unregulated, but 18V sounds way off!). Maybe this is the problem? Check the rectifiers on P.S.Board and eveyrthing.
I did the measurements on the Power PCB with the J101 terminal disconnected and the readings were correct. When J101 is connected, the 5v reading drops to 4.5v. I'll start at the beginning and replace all the capacitors in the source (I was waiting to fix the problem to do so).
Ok, but did you measure the other outputs of the PSU? It has several other outputs as indicated in wiring diagram - not only the J101 connector. I personally think it would be best to first measure everthing around the PSU board (it can be taken out quite easily, only remove two screws at heatsink), to make sure if the problem lies on power supply. That's because when changing electrolytic caps, it's always possible to introduce some additional problem by human error (it happens even to the best technician), and then you'd have to troubleshoot two faults instead of one. You can easily rule out the caps in this case, as they are for filtration (except the voltage doubler, but this is only for 18V), if you have a scope, but even with a DMM. If the caps are acceptable (meaning that they work, not that they don't have to be exchanged for best operation due to age), then you know that the problem is elsewhere and don't go ahead with changing them yet, avoiding the possibility of introducing additional problems. Just my 2 cents, though.
The fact it drops to 4,5V definitely indicates something, in my opinion. The regulator doesn't seem stable or the current draw is too high (does the regulator get hot quickly?). So, it might really be a cap, but it could also be something else in the PSU, like the reg itself, for example. Did you check if the power supply lines have excessiv ripple?
The fact it drops to 4,5V definitely indicates something, in my opinion. The regulator doesn't seem stable or the current draw is too high (does the regulator get hot quickly?). So, it might really be a cap, but it could also be something else in the PSU, like the reg itself, for example. Did you check if the power supply lines have excessiv ripple?
That's correct, regarding the voltage drop, but I didn't understand what you mean with "DC", the voltage is clearly DC not AC, although not regulated. It could also be a bad connection/solder joint to the diode, better check it with DMM in diode test mode. I see you have a different SM/schematic, which actually shows the unregulated voltage, indicating 17V, so my previous comment about 18V maybe being excessive can be disregarded. On another note, could you tell me where you got this schematic/service manual? As I'm still repairing the CD73 and I only got three manuals: a limited manual with schematics only (different from yours, lower quality and missing these indications) and two SM of Philips CD303, which obviously is not exactly the same player (although very similar). It would be very useful for me to have this clearly better schematic for reference for the CD73 I'm repairing, thanks.
The Led power is the SLP171D model (red), the maximum voltage is about 3v (I don't know if being double influences).
https://www.datasheetarchive.com/?q=SLP-171D
The supply voltage of the led is 17v (19v in the CD303 scheme) and after the drop of R827 it gives the correct supply voltage. By not effecting the voltage drop and not working, the led indicates that said led is "burned out".
But as you say that is a mistake to look at later.
Email me by mp for the schematic.
https://www.datasheetarchive.com/?q=SLP-171D
The supply voltage of the led is 17v (19v in the CD303 scheme) and after the drop of R827 it gives the correct supply voltage. By not effecting the voltage drop and not working, the led indicates that said led is "burned out".
But as you say that is a mistake to look at later.
Email me by mp for the schematic.
Right, seems clear then, and yes, apparently a non-critical fault (but COULD still be indication of some trouble! did you do the check of the rectifiers and/or ripple on supply voltages, including the unregulated ones? it just crossed my mind that the LED wouldn't light up if it received AC instead of DC due to some fault of rectifiers...). But it could also be a bad (solder) connection at the LED itself, I find it quite strange for the LED appearing to be burnt out, this doesn't happen often, unless they are driven above their max voltage or for too many hours. I don't think either would have been the case.