Hi everybody,
a couple of weeks ago I bought an old Sony CDP-195 (1991/92) at the flea market. The unit was sold for 10 euros as “non working”, so it looked like a good chance to try to learn something about CD players, which I’m not really confident with.
The player looks 95% dead. The only thing (half) working is the tray: it opens but it doesn’t close. It only does If you switch the unit off (with the tray open), and then switch it back on. This leads me to exclude contacts or mechanical problems. Microswitches have been cleaned anyway, as described in Mooly’s CDP-790 thread.
The front panel seem to work: all the buttons respond correctly, displaying the respective mode or symbol (Play, Stop, Pause, Track selection, functions etc.) except that nothing happens.
All the rest is dead. No action by the sled and spinning motors, no movements of the pickup, no light from the laser. When a CD is inserted, the BD Board doesn’t lift up, so the disc doesn’t lock to the platter and falls around.
The tensions printed on the Main Board have been tested and look ok. Discrete components have been tested and look ok.
Anyway, even if the BD board is disconnected (ribbon cable detached), and the player is in stop mode, transistors Q202 and Q208 become hot quickly. Not sure whether it’s a problem or not, maybe it’s just the way it should be, since Q208 has a heatsink.
Tension on pin 1 (+7v) and 6 (+5v) of the BD Board ribbon cable socket are ok on the Main Board side.
I suspect there’s a problem with IC102 (LA6532M), the one that controls the motors. I checked the tensions in Play mode, and I have just 2,7v on the pins 18/19 (controlling the spindle M) and 0v on pins 12/13 (controlling the Sled M).
I’m tempted to replace the IC, but I’m not 100% sure. I read everywhere that replacing the laser unit will solve almost any problem, but I suspect this time the fault is elsewhere.
Any suggestion will be greatly appreciated. Thank you.
--------
PS Service Manual attached
PPS For the ones following my other thread about the infamous Transylvania cassette recorder/player, the unit is still on hold, but I haven't give up. Just had enough of it. Sooner or later I'll come back to it.
a couple of weeks ago I bought an old Sony CDP-195 (1991/92) at the flea market. The unit was sold for 10 euros as “non working”, so it looked like a good chance to try to learn something about CD players, which I’m not really confident with.
The player looks 95% dead. The only thing (half) working is the tray: it opens but it doesn’t close. It only does If you switch the unit off (with the tray open), and then switch it back on. This leads me to exclude contacts or mechanical problems. Microswitches have been cleaned anyway, as described in Mooly’s CDP-790 thread.
The front panel seem to work: all the buttons respond correctly, displaying the respective mode or symbol (Play, Stop, Pause, Track selection, functions etc.) except that nothing happens.
All the rest is dead. No action by the sled and spinning motors, no movements of the pickup, no light from the laser. When a CD is inserted, the BD Board doesn’t lift up, so the disc doesn’t lock to the platter and falls around.
The tensions printed on the Main Board have been tested and look ok. Discrete components have been tested and look ok.
Anyway, even if the BD board is disconnected (ribbon cable detached), and the player is in stop mode, transistors Q202 and Q208 become hot quickly. Not sure whether it’s a problem or not, maybe it’s just the way it should be, since Q208 has a heatsink.
Tension on pin 1 (+7v) and 6 (+5v) of the BD Board ribbon cable socket are ok on the Main Board side.
I suspect there’s a problem with IC102 (LA6532M), the one that controls the motors. I checked the tensions in Play mode, and I have just 2,7v on the pins 18/19 (controlling the spindle M) and 0v on pins 12/13 (controlling the Sled M).
I’m tempted to replace the IC, but I’m not 100% sure. I read everywhere that replacing the laser unit will solve almost any problem, but I suspect this time the fault is elsewhere.
Any suggestion will be greatly appreciated. Thank you.
--------
PS Service Manual attached
PPS For the ones following my other thread about the infamous Transylvania cassette recorder/player, the unit is still on hold, but I haven't give up. Just had enough of it. Sooner or later I'll come back to it.
Hi,
Does the motor close the tray when you push it a little with the finger ? Looks like a ROM has been shorted perhaps, do you suspect it has been opened or tweaked already ?
Not sure you should spend more monney to fix it by tries and errors in the dark. And it is not a high end cd player, a basic model only.
But at 10 e if you think twice, you have a lot of parts to desolder for future diy, a power supply, some op amps and a nice case. Not a bad deal.
Does the motor close the tray when you push it a little with the finger ? Looks like a ROM has been shorted perhaps, do you suspect it has been opened or tweaked already ?
Not sure you should spend more monney to fix it by tries and errors in the dark. And it is not a high end cd player, a basic model only.
But at 10 e if you think twice, you have a lot of parts to desolder for future diy, a power supply, some op amps and a nice case. Not a bad deal.
Hi diyiggy,
Thanks very much for your reply. I have a (bad) update to it.
I found I had an ICP open, which seems to be a quite common fail on Sonys CDP. I replaced it with an identical one, and nothing appeared to change.
After a couple of times of switching on and off for testing, the unit completely died. No longer illuminating display, no tray open, nothing. All the component are cold (as you’d expect from any respectable corpse).
Both the ICP used in the circuit are ok. I checked tensions on any indicated point and it looks like I have nothing nowhere, except at the bridge output and on pin 1 of the IC101 regulator. Power supply capacitors look ok.
I have to investigate further to find out the way to at least restore the unit at the previous conditions, so that I can start over the fault finding.
As far as the “Does it worth?” question, yes I know it’s actually pointless to spend such time (and likely money) on such a cheap and old piece of gear, but I’m doing this mostly for learning purposes, and I’d rather prefer to lose some (little) money ad learning something, than save 20 or 30 euros and learn nothing. Understanding its circuitry and possibly the ways it can fail, would be virtually priceless for me. If my skill level and mastery of the subject will grow, I hope to be able to put my hands on some high end piece from the Golden Age of hifi, sooner or later.
PS I don't think anybody tried to service the unit before me.
Thanks very much for your reply. I have a (bad) update to it.
I found I had an ICP open, which seems to be a quite common fail on Sonys CDP. I replaced it with an identical one, and nothing appeared to change.
After a couple of times of switching on and off for testing, the unit completely died. No longer illuminating display, no tray open, nothing. All the component are cold (as you’d expect from any respectable corpse).
Both the ICP used in the circuit are ok. I checked tensions on any indicated point and it looks like I have nothing nowhere, except at the bridge output and on pin 1 of the IC101 regulator. Power supply capacitors look ok.
I have to investigate further to find out the way to at least restore the unit at the previous conditions, so that I can start over the fault finding.
As far as the “Does it worth?” question, yes I know it’s actually pointless to spend such time (and likely money) on such a cheap and old piece of gear, but I’m doing this mostly for learning purposes, and I’d rather prefer to lose some (little) money ad learning something, than save 20 or 30 euros and learn nothing. Understanding its circuitry and possibly the ways it can fail, would be virtually priceless for me. If my skill level and mastery of the subject will grow, I hope to be able to put my hands on some high end piece from the Golden Age of hifi, sooner or later.
PS I don't think anybody tried to service the unit before me.
As far you are aware about that, it is okay and your freedom of course to try and an interresting task ! 🙂
Assuming the unit had no short(s), the ROM have not been impacted by an electrical disease, we can expect the ICs are the most solid parts of an electronic unit. I am not an EE, but in a same scenario, I would check all the fragile parts that maybe suffer for a reason or another : diodes, switches, relays, trimable resistors, pushable interuptors on the pcb if there, tantal caps. Then bigger chemical ones around the IC, cold joints. Notice some carbon resistor migth have drifted but not sure it is a possible culpritt there.
SO if you have zero current, check first : fuse or poly switcch, then rectifier and smoothing cap. If it is a SMPS pwer supply check the big capacitor rated several hundred of volt (be carefull with that, it can kills you).
You will need to work on an ESD free plan and same for your hand (Earth connection from the body), a good solder station as some parts needs to be lifted for control and of course a DVM.
I hope a teached EE from the forum or a member with greater knowledge than I, will help you with better advices.
good luck for your projects
cheers
Assuming the unit had no short(s), the ROM have not been impacted by an electrical disease, we can expect the ICs are the most solid parts of an electronic unit. I am not an EE, but in a same scenario, I would check all the fragile parts that maybe suffer for a reason or another : diodes, switches, relays, trimable resistors, pushable interuptors on the pcb if there, tantal caps. Then bigger chemical ones around the IC, cold joints. Notice some carbon resistor migth have drifted but not sure it is a possible culpritt there.
SO if you have zero current, check first : fuse or poly switcch, then rectifier and smoothing cap. If it is a SMPS pwer supply check the big capacitor rated several hundred of volt (be carefull with that, it can kills you).
You will need to work on an ESD free plan and same for your hand (Earth connection from the body), a good solder station as some parts needs to be lifted for control and of course a DVM.
I hope a teached EE from the forum or a member with greater knowledge than I, will help you with better advices.
good luck for your projects
cheers
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